I did the class independent study in spring '06. I used this book:
http://www.bestwebbuys.com/Introduct...?isrc=b-search . I read the relevant chapters (iran, nigeria, britain, russia, china, mexico) starting a couple months before the test. After this, I took an ethel woods practice test and got a 5, then read the ethel woods book and took the second practice test (also a 5). My AP grade was a 5 as well, so the textbook linked to above certainly worked for me, and the Ethel Woods was a good review/summary/organizer of information.