1. AP Human Geography Crash Course
by Dr. Christian Sawyer
2015 or latest edition
This book is a great review resource for information that is required on the AP Exam, broken down into chapters and areas that are needed to be mastered.
2. Cracking the AP Human Geography Exam 2015 or latest edition
by The Princeton Review
This book is a great review resource for information as well as containing multiple practice tests.
I would suggest the first book first, and then the Princeton Review. Both books together would be a fantastic way for your child to really break down the information and then practice with the practice tests.
We will be using these books for our month long review in preparation for the Exam starting in late April.