1. Five 'modules' all up- four are technical (FIN, AAA, MAA and TAX) which can be completed in any order and the final one which can only be done after all the others is EBA (ethics).
2. You can do 3 modules per year as it's a trimester timetable. The technical modules are usually offered in pairs (e.g. FIN/MAA are offered at the same time, and AAA/TAX offered at the same time) so you can choose one or the other. In theory you should be able to finish the technicals in 4 consecutive trimesters assuming you don't fail (i.e. 1 and a bit years).
3. The subject 'times' cross over in that the next module could commence before your current subject's examination. That being said, when we say 'module commencement', that just means you have enrolled and know when your focus sessions (similar to tutorials) will be- your actual studying or attendance at focus sessions won't commence until a week (or so) after you have finished your examinations. Refer to the timetable below- particularly look at the gap between the 2nd and 3rd trimesters with when an exam starts and when "FS 1wk" actually is.
Note that EBA starts sufficiently later in the year compared to the normal technical modules so that you can get your results first before commencing EBA (since it's a requirement that you have passed all four technical subjects- in any order).
For timetable information, refer to
http://www.charteredaccountants.com.au/Candidates/The-Chartered-Accountants-Program/Timetable and click on the first link to the "Chartered Accountants Program".