Seriously, don't waste your money. The school you choose to study with will provide all course notes and literature required. Then after you have studied hit the question bank. It's not hard - theres nothing above GCSE level in any of the exams, theres just a fair amount to learn.
You can't really study for this like a degree and try and absorb everything and then take the exams; the questions are so poorly written, often translated from another language, that unless you have seen some of them before you don't stand a reasonable chance of getting the expected 95%+ average.