I used the Barrons AP US Government and Politics. I had a gift certificate to a store and it was either that or Cliff Notes. I thought Barrons had a better index. I got the book on 4/27 but didn't start reading it for a week or so. I probably read a chapter or so a night. I had given it break over the past few days. The book study questions for each chapter and two practice tests. However, the book did have several typos and I think wrong answers. I also used the practice test in the CLEP study guide.
What's next might be Dantes History of the Vietnam War to satisfy an elective history course I must take.