My wonderful volunteers wrapped hundreds of books in categories such as "if you like..." Harry Potter, Percy Jackson, Magic Tree House, Ivy&Bean, Wonder, Diary of a Wimpy Kid, and other popular types of books. Kids pick one from the shelf and wait to unwrap it when they get back to their class. This builds the excitement and enthusiasm.
I love hearing, "I can't decide!" "I wonder what it will be!" and "Can I pick another one? I loved the last one I unwrapped!"