I sat my test in December and recently offered a place to my course. My best advice is to use their sample test and if you are fine wth that you should do fine as they were pretty much the same questions using different examples. Others have suggested the real thing was harder but I didnt really think so. Before I sat it I didnt realise there would be the essay component but that is only marked as satisfactory or not (no score as such) so you should be fine with that (if you can look up some brief info on essay layout, although only 1 page answer was required based on an article they gave you). I personally enjoy maths and got higher on that than the literacy (39/40 for maths and 36/40 for literacy), however it has been 11 years since I completed year 12 and mainly been in customer service roles since so I havent always been able to use it. The practice questions definitely helped - I know I wouldnt have got those results if I didnt use that.
Most importantly, READ EVERYTHING FULLY AND SLOWLY and dont assume the answer without doing your workings out, then look at the options (5 multiple choice to choose from) and mark your answer. Also, no calculators allowed. If you are really unsure dont waste time and go to the next question and come back at the end (just make sure you do the marking sheet correctly if you skip a question). You will always be able to eliminate some answers quickly even if you dont know correct answer so that will make the odds better if you are guessing.
I think the test counts for a bit as I assume my results were quite good as I didnt have to do an interview, however others have had different experiences so it really depends on whose offering the course and demand, etc, but I think initially it may be based on the test then any vacant spots after that initial intake will depend on interview. I only booked my test and did practice questions 2 days before so I wish you all the luck. I start my course next Monday.