What can I say about the Australian School System... Best start at the beginning. The Australian School System has three levels: Primary, Secondary, and Tertiary. These tropes are often true about schools in Australia:
- Elevator School
- School Uniforms Are the New Black: School uniforms are the norm rather than the exception for both Primary and Secondary levels of education. The main exceptions would be in remote area schools where there simply aren't enough students to justify a production run, senior colleges which are often attached to universities (Australian senior colleges are closer to American prep schools than British senior colleges), and distance education where they aren't physically attending a school most of the time. (Indooroopilly State High in inner Brisbane, QLD is one of the few exceptions to that. It was used as a trial to the US style dress code and while it was never expanded to the whole state it was never changed back there either).
(Keep in mind that education, under the Australian Constitution, is something the states have power over, and so, the education system is Queensland is different to that of NSW.)
One thing that can confuse those from the Northern Hemisphere is that in Australia the calendars synch up. The school years starts in late January/early February and the first holiday period comes at Easter, the Good Friday holiday generally marking the start. Winter holidays last a couple of weeks and come in late June or July, though this varies from state to state. Another week or two (depending on the state) in September and then the school year ends in late November or early December.
One thing this does is it makes the school grade (usually called a Year rather than a Grade) map directly to age. For example, Year 7 students will be either 12 or 13 at some point during the year.
In most states, primary education begins at the age of five—the exception until recently was Queensland, which started school at 6 but which has recently added a year to bring it in line with the other states. The name of the first year of primary school actually changes from state to state, but, for the sake of clarity, it will be referred to as Reception here. Primary school lasts from Reception (age 5) to either Year 6 or Year 7 (age 11-12), again varying from state to state (for instance, in South Australia, schools are divided between Junior Primary - Reception to Year 2 - and Primary - Years 3 to 7). In Years 3, 5, and 7, students sit the NAPLAN (though everyone sill calls it LAN) test. LAN stands for literacy and numeracy, and the tests have no bearing on future schooling - they just get used to compare individual, state & territory, and national averages.
In NSW, Smarter students can opt to take the OC test in Year 4. If successful they can attend an Opportunity Class full of other bright kids in Years 5 and 6. At Year 6 many students will take the secondary schools test. These test is then used to apply to 'selective' schools, government schools that are selective in which students are admitted, with the high schools that produce students with high ATARs being pickier in their selection. Victoria has something similar, but with fewer selective schools, and the test's just called the "Entrance Examination for selective schools".
Secondary school usually starts at either Year 7 or Year 8, although most area schools will start secondary school in Year 7, regardless of state. In Year 9, students have to sit the LAN test again, which also has no bearing on future schooling for the students. In Year 11, students start their ACE certificate. The name and the curriculum of each certificate varies from state to state yet again. The first year is called stage 1, and the second year, year 12, is called stage 2. In Australia, it is mandatory to complete high school up to Year 12, unless you immediately move into full-time employment on completing Year 10, under an act nicknamed the "learning or earning" law.
In NSW, Year 7-10 has a few tests, like SNAP and ELLA, taken in Year 7 and 9 to assess numeracy and literacy respectively. At the end of Year 10, all NSW students sit for the School Certificate, a state-wide exam which assess English, Mathematics, Science, Australian History and Australian Geography (you technically start the School Certificate course in Year 9, but, as of recently, only Year 10 stuff was assessable). Previously, after Year 10, students could 'drop out', this has recently been pushed back to the end of Year 11. Year 11 and 12 are where students do the 'Preliminary Higher School Certificate' and 'Higher School Certificate' (HSC) courses, with Year 11 lasting for 3 terms, one lower than usual, while Year 12 lasts the usual 4 terms. This is because the HSC exams are at the beginning of Term 4, so a term is taken from Year 11 and used as part of the HSC course. In Year 11, 12 'units' must completed in order to complete the Preliminary HSC, required to do the HSC. Most subjects are 2 units, but Extension 1 Math and English are each 3 units (1 unit plus the base 2 units of the Math/English subject), and one unit subjects also existing. Successfully meeting the course requirements is needed in order to the course in Year 12. In Year 12, only 10 units are needed in order to get a ATAR, but more can be done, with your 10 best units (marks-wise) being counted. However, the English (Standard or Advanced, an English course is compulsory) mark is always included, regardless if it was part of the best 10 units or not. In addition, Extension 2 Math and English (4 units apiece), as well as Extension History and extension course for languages also exist, but you need to continue on the 'base subject' (eg. Ext. 1 Math/Eng, Modern/ Ancient History) in order to do the Ext. subject. At the end of the HSC course, you do the HSC exams, which determines your ATAR.
The end of Year 12 differed from state to state, but, as of 2009, is being standardised into the 'Australian Tertiary Admission Rank' (ATAR), which will be introduced into all states and territories except Queensland. The HSC (what is currently in place in NSW) are a set of tests undertaken by students who have studied the course in Year 11 (the only year with 3 terms) and Year 12, which starts around November. Most of the tests around the same time, except for the practical component for Performance Arts, Visual Arts and Music subjects, where the examiners have to travel to each school to assess students, so they start earlier. After sitting for the HSC, marks are awards, sorted into 'bands' (with 'Band 6' being the highest, like the earlier 'School certificate exams'), and from that, a student's ATAR is derived, which is a student's rank in the state. The ATAR is used to apply for the majority of courses in university. The needed ATAR is primarily based on the demand for that subject at each particular university.
In Queensland at least though the process is a little different. Grade 11 and 12 students do up to 6 subjects with English and one of two Maths streams known as Maths A and Maths B being compulsory. Then in late August there is a state-wide tests known as the QCS (Queensland Core Skills) Test that is supposed to test general reasoning. At the end of the year the results from the QCS test and Academic subjects are combined to generate an OP (Overall Position) score which is compiled across the state on a bell curve. OP 1 is the best and OP 25 is the worst. University entrance requirement are a combination of academic difficulty and number of applicants (generally done in September). Low application rates can force the OP requirement down. The recent popularity of taking a gap year (a year of full time work or travel between high school and university) has lowered OP requirements of several courses. This troper's course, for instance, dropped from an OP 6 entry to an OP 10 entry. This is not necessarily a bad thing; the QCS test and its results are notoriously bizarre, and the OP entry cutoff is usually completely arbitrary and only in place to stop courses from getting overcrowded.
In Victoria, secondary school starts at Year 7 (the convention in Victoria is to use "Grade" for primary school and "Year" for secondary school) and continues in a similar fashion to the NSW system. However, at Year 11 (or at Year 10 if the student elects to start a particular subject a year early) students choose their classes as part of a complete two-year course to achieve their Victorian Certificate of Education (VCE). For every subject, excluding mathematics, there are 4 units: Units 1 & 2 are taken in the first and second semesters of Year 11 respectively, and Units 3 & 4 are taken in the first and second semesters of Year 12 respectively. To pass a particular subject, it is not absolutely essential to take Unit 1 & 2 (so it is possible to take up a subject at year 12 level even though you never touch the year 11 material, though this is not common, for obvious reason) but it is necessary to pass both Units 3 & 4 if you want that subject to contribute to your final score. By the way, it is entirely possible for a year 9 to take up one (or more) Unit 1 & 2 subject, and for a year 10 to take up one (or more) Unit 3 & 4 subject, if the school allows the student to do so 
Students are required to complete English and at least three other subjects at the 3-4 level (note, a total of 16 units (including Units 1-2 must be done in order to obtain a VCE certificate). Their ENTER scores are calculated on the basis of their total scores for English and their three best other 3-4 units plus 10% of the scores for the 2 next highest 3-4 units  (all scaled up or down depending on difficulty  of the subject). The maximum ATAR (used to be called ENTER) score one can get is 99.95 (roughly top 0.05% of the student population, usually around 40 students or so); the minimum ATAR score possible is technically 0.05 (roughly bottom 0.05% of the student population), though any score below 30 will not be revealed since they probably do not really indicate the student's ability (anyone who gets this kind of score probably doesn't study instead of being stupid) and might be extremely de-motivating (it sucks to be in the bottom 0.05% of the student population). Note that an ATAR score is based on percentile rather than on the normal distribution - so a score of x will indicate that the student has higher or the same total score as x% of the student population.
Mathematics starts as (from hardest to easiest) "Advanced General Maths" 1 & 2, "Maths Methods" 1 & 2, "General Maths" 1 & 2, or "Foundation Maths" as an extremely basic substitute for General Maths (which disqualifies the student from any other Maths subjects). At Year 12 students can take "Further Maths" 3 & 4 (to follow General Maths—the least difficult 3-4 maths), "Maths Methods" 3 & 4 (of middling difficulty), or "Specialist Maths" 3 & 4 (to follow Advanced General Maths—the most difficult).
The range of subjects is quite wide, consisting of very obscure subjects like Classical Greek, Classical Societies and Cultures, Albanian... Not every school offers the same range of subjects, but all will offer core English and most will offer Maths Methods, Chemistry, Biology, Physics.
In Western Australia the high school system is currently very much up in the air and confusing. The only people who can give a real explanation of the graduation system and tests of any one year are those who are graduating in that year. This is due to the fact that WA was introducing a new educational system before an Australia wide education system was introduced. This caused the already partially introduced OBE system to be derailed, changed greatly and slowly introduced without much research into it's effectiveness meaning that a lot of things that were introduced or recommended last year have been taken out or changed this year. Basically WA is very to the other states except our graduation exam is called the TEE (Tertiary Entrance Exam) and is optional and only taken if the applicant is planning a Tertiary education, If not then students have the option of taking wholly schools-assessed subjects.
In South Australia the high school system starts at Year 8. Years 8 to 10 are sometimes known as 'middle school' depending on the school. Some schools are focal schools for gifted students, running programs known as SHIP or IGNITE. Years 11 and 12 are combined into the South Australian Certificate of Education (SACE), which result in a Tertiary Entrance Rank for those interested in going on to further study. SACE used to entail studying 5 publicly-assessed and/or school-assessed subjects per year at Year 11 and Year 12 level; however, this has recently been decreased to four subjects and a year-long 'research project'. Neither teachers nor students are impressed by this, but it looks like New SACE is here to stay, at least for the moment.
Tertiary education in Australia is provided by a range of universities, private colleges, and technical education centres. One key element of the Australian tertiary education system is HECS, the Higher Education Contribution Scheme. The Australian government supports a very large number of places in various universities and technical courses. Australian citizens with no tertiary qualifications who are accepted into these supported places have most of their costs covered by a government loan with no real interest and repayments linked to the income tax system, which means no repayments are required until you're earning a wage that will cover both the repayments and costs of living. This means that tertiary education is substantially more accessible to students with disadvantaged backgrounds than in America. That is not to say the system is perfect - disadvantaged students often have lower reslts across the board, making it hard to access a supported place, and it can be very difficult to meet the cost of living while having enough time to study. Despite schemes such as HECS, Australian university attendance is quite low; as of 2008 only 27% of Australians were enrolled in or had completed tertiary education, compared to 70+% of Americans. This is probably because Australia offers a vast array of apprenticeships, internships, and TAFE (Technical And Further Education) courses that allow people to move directly into full-time work on completing high school, either through on-the-job training or through receiving training as a component of their secondary learning from year 10 onwards.
Universities in Australia follow three-year undergraduate course, with a wide range of courses rather than majors. Professional degrees like Law, Medicine, Dentistry, Pharmacy and Engineering used to be offered widely as undergraduate courses (4, 5, 5, 4, 4 years respectively). However changes are being made, most radically at the University of Melbourne, which abolishes its original around-90 undergraduate courses to only 6 core courses, with a wide range of majors. Professional degrees are now all postgraduate at the University of Melbourne. Three-year undergraduate course is still followed however. The change was not without criticism, as students have to study longer, pay more (postgraduate courses are not all funded by the government) and there was a significant downsizing as the result of the reduction of number of courses. At other universities, Medicine has been (is being) moved to postgraduate at many (but not all) universities. Engineering remains undergraduate, but postgraduate options are being made available. Law, Dentistry and Pharmacy are also moved to postgraduate at some universities, however the norm is still undergraduate.
Entry to University in Australia is relatively simple, because most entry decisions are based on final ATAR score (above). Every year, an university will release previous year's cut-off points, and they will indicate fairly strongly what the cut-off points of this year will be (the cut-off point will generally be the ATAR score of the weakest student who got entry (through normal means) the previous year). All the student has to do is to get above that ATAR score and he will be virtually guaranteed entry - no requirement of personal statements or extracurricular activities or things like that. Most entry decisions are made purely on secondary academic performance, except for Medicine and Dentistry, where generally, an additional test is required, and an interview. Final decision is made taking into account all there components, though different universities will put different weights on the components.
Higher Education in Australia is generally considered one of the best. Although it can't really be compared with giants like the United Kingdom and the United States, it does have an impressive record, with its 3 best universities (the University of Melbourne, the Australian National University and the University of Sydney) in the top 50 of the QS World Ranking. This, compounding with the fact that entry is relatively easier, it's cheaper, and there's a higher chance for migration after study, Australia is one of the top attraction for international students. Interestingly, if one is to visit the University of Sydney or the University of Melbourne (or ANU), one should find an amazingly overwhelming number of international students (especially Chinese and Indian), especially in courses like Commerce.
- This has been done before. It might even be technically possible for a year 7 to take up a Unit 3 & 4 subject, but this apparently has never occurred.
- or, in some exceptions, another English subject such as Literature or English Language (i.e. linguistics, etymology etc.) or ESL (i.e. English as a Second Language, for international students) - it's possible to do more than one, but only the two highest scores will be counted in the final score
- Though it's possible to study more than 6 subjects at 3-4 units level, only the six highest scored subjects will be counted. The fifth and sixth subjects are optional.
- The word difficulty might be misleading. The key to whether a subject is scaled up or down depends on whether the population of students studying consists of mostly low-performing students, mostly high-performing students or a balanced range. Students are ranked with each other in order to determine their score, hence it's clear that it will be easier to compare yourself with a low-performing population rather than a high-performing population. Scaling will be made accordingly to ensure that the difficulty of getting a particular after-scaled score for every subject will be the same.
- Again, it's possible to take more than one, but only 2 out of 3 will be counted. Most students will take Further + Methods or Methods + Specialist.
- conducted by ACER who provides external professional testing service, which tests students on EQ and IQ, though does not exactly provide an IQ or EQ score), but again students are ranked against each other and a percentile score is given
- which has quite an unfortunate acronym, ANU. Why? Put Student after it.
- though with the AUD going strong, we can't really make this claim anymore
- 50% of Bachelor of Commerce students at the University of Melbourne are international students. Coupling with the fact that the majority of the rest are East Asian-Australian, one might not be surprised to find that sometimes it seems the University of Melbourne looks more like a Japanese university instead of Australian