<p>Excellent choice! The “5 Steps to a 5” series is in my opinion the best companion one can have when studying for the AP tests. I’m going to be self-studying for the AP European History exam and that’s the book to buy. </p>
<p>I’ve never used Barron’s but I do have a few Princeton Review books. They’re okay - not as good as the McGraw Hill variety since I find they give a very cursory overview of the subject matter. If you can find a cheap copy of one of their books, however, it may be worth it just for the practice questions, which tend to be good. </p>
<p>Then again, I only took one diagnostic test before my AP US History exam and I did extremely well on the exam. When it comes to the history exams you just need to know the material.</p>