Did it from the books. When I did my exams, the best series was Ron Campbells (this was before Trevor Thom wrote his). Had no problems myself - first time pass.
I echo the advice from others, work through each section in whatever book you're using, then check understanding from any test questions which are included in the book (or are available seperately). If the information hasn't stuck, go over it again until it does.
My "top tip" for learning is not to just read the book, but to make notes as you go along. The act of writing down what you've just read seems to make it stick better. Once you read over those notes, you may also see areas where you haven't fully understood what the book said and now have the opportunity to rectify the deficiency. I then use my notes for my final pre exam revision. Works for me!
Good luck.