you'll probably find your solution in this article:
http://www.tek-tips.com/viewthread.cfm?qid=1428025&page=3
Keep in mind the very last point - talk to your printer to find out what sort of duplexing technology they have. Printing a 'rough' version of your book at home, and taping the individual pages together to create a mock-up book is also a great idea - it helps ensure your printer understands exactly how the book is supposed to look when printed and bound (that way you can ensure they're on the same page as you. Get it?...)
