First of all, I would buy the Barron's AP Art History review book, it has a wide variety of different works and will help you score as many points as you can while learning as little as possible. I would also suggest doing some other research or work on the side for Art History if you are serious about getting a good score. It's not an easy test, and you really have to know your stuff (which is more than what's covered in the Barron's book).