Nightmare at the Book Fair by Dan Gutman

Trip Dinkleman just wants to make it to lacrosse tryouts on time, so he isn't thrilled when a PTA mom asks him to help her move some boxes of books for the book fair. When a book hits him on the head while he's reaching for a box on a high shelf, it's just the beginning of Trip's adventures through time and space. He wakes up and finds himself in what turns out to be only the first of many weird places. Trip isn't sure whether what's happening is real or just a crazy dream, but whatever it is, it isn't long before he's ready to go home! Review by Joyce Levine