This is not the correcy use of Columns, search for "Book Fold" in the Help,
this may be more useful. This format is used for booklets, etc. Tip, ignore
any reference to Master and Sub-documents, this feature is very buggy.
If the book is going to contain a large number of pages, I would create the
book first in a "normal" layout, i.e. no columns, etc. and sort out the
layout at the end of the writing process.
Hope this helps
DeanH

And also the following for larger Books. Apologies for the multiple postings
my system is having hick-ups.
http://daiya.mvps.org/bookwordframes.htm

Also see the following article:
http://word.mvps.org/FAQs/Formatting/BookletPrinting.htm

Hope this helps
DeanH