Theme Park Insider has published an unofficial, unauthorized, in-depth Wizarding World of Harry Potter Guidebook. The 63 page booklet covers all of the major rides, attractions, and restaurants as well as offering tips for visiting each one.
I can tell you that when we visited the Wizarding World of Harry Potter, I would have loved to have had this booklet! The book even includes comments from the Park designers and the stars of the movie! Holy Cow, my kids would love this book!
Read the entire blog post about the book form Theme Park Insider here: http://www.themeparkinsider.com/flume/201410/4257/