Book printing is a very specific type of printing. Finding the right printer for your book can be a harrowing experience for the novice. Normally, this is silly. But because book printing is very particular, it can be costly if you design a book that conflicts with prepress or press capability. Unless you understand book printing, you should let a designer or print buyer coordinate the printing for you.
Book printing is specific with regard to sizes, page count, inks, photos, prepress, etc.
Of course, you could spend a lot of time receiving an education about print from printers and salesmen and design a book that is printable. This book covers every technical aspect of the industry. The following book sizes will cut your printing costs dramatically. Printers buy paper in bulk at certain sizes. Page size is contingent on the most economical fit for the paper that can also be accommodated on press.