Doing it in September. So far I've been trying to get to grips with organic chemistry again. Been using the "Organic Chemistry for Dummies I", and associated workbook. They're on amazon if you can't find them from a real bookshop. The khanacademy videos (google it) are very good.
You really need to have a look at the pagingdr forums. It's for Australians but their GAMSAT information is (unsurprisingly) very detailed.
You can find some GAMSAT sample papers by googling "GAMSAT sample paper" or similar.
Need to have a look at Physics soon, so going to have a look at an old A level textbook.
Section I looks tricky, but is essentially just reading and processing information. Not much really you can do for this apart from read more, expand vocabularly. Looking at the sample papers, there seem to be a few questions where the answer could conceivably be either one of two options.
Section II will be a sod. I can't remember the last time I had to hand write a work of any length. Not quite sure how to prepare for that.