First try to create a PDF file of the book as described in this Apple Document: iPhoto '11: Preview a book, card, or calendar before you order or print it. If you can't then that's the problem.
If that's the case boot into Safe Mode, Mac OS X: Starting up in Safe Mode, and try creating the PDF file again. If that's successful preview the PDF file for any errors before ordering and keep the PDF file to compare to the book when it arrives.
Then order the book again while booted in the Safe Mode. What size book are you trying to order?