For Biology I mainly used Kaplan book (the information I feel was not enough of a review) but if I took it again I would probably use Cliffs AP Bio review. For QR Kaplan does a good job of going over the basics you need to know also Chad's videos on coursesaver.com are very helpful for Gen Chem, Ochem, and QR section. Also I took the DAT before taking some core biology classes such as microbiology, anatomy, physiology, genetics, evolution.