I'd recommend the AA theory book, and especially getting some theory CD's for the PC. I used both of them and passed fine. THe CD's are expecially good, because its pretty much like taking your test, but on your own PC, and they also have hazard preception tests, so it is very very good, well worth the money
I have both the CD's and the book, if your interested in them
I recommend the theory cds as weell i could never have passed the theory test without them i got mine from www.learnerstuff.co.uk cheaper than amazon when you take into accont amazons rip off postage chargees
