You can also take the practice exam at
AP US History | AP Exam Review Course
its pretty decent and it will give you your score as if it were scored by the college board. In other words, it'll tell you if you got a 1,2,3,4,5 etc. If you can get a 3,4,5 on that exam you are well prepared for the exam, if you get a 1,2 you better start reading up lol.