<p>What are the best books to learn and review?? I have PR right now.. however some chapters are adumbrated and I would like to go more indepth. Are there any books out there are will allow me to do this? Can I find free real practice tests anywhere? I've seen people post AP exams from past years and I don't know where to find them. Thanks in advance.</p>
<p>According to my teacher, Kaplan has a pretty strong review book.</p>