Reddit reviews Biology for the IB Diploma

This is a lifesaver for french, even if you are doing ab initio!
http://www.amazon.com/Standard-Revision-International-Baccalaureate-Diploma/dp/1904534252
for bio this is FANTASTIC for studying
http://www.amazon.com/Biology-IB-Diploma-Andrew-Allott/dp/0199151431/ref=sr_1_1?s=books&ie=UTF8&qid=1344831709&sr=1-1&keywords=ib+bio+study+guide
The chem and english ones in this series are great too...I would easily attribute my 7's to these books! :)

the official textbook for bio is not worth wasting your money on...I don't think I've used it in the last year because it is so badly organized. I wouldn't worry about books being cheaper on amazon, I bought all of mine there and they are identical but saved me so much money.
Hope this helps, let me know if you have any other questions :)