The best program for *writing* a book is a word processor you know how to
use and are comfortable with, so that it doesn't get in your way. If that's
Word, use it. If it's WordPad, WordPerfect, or some other program, use that.
As long as you're producing text, it won't matter.
The best program for *formatting* a book is one that can handle the layout
you need. If you're trying to produce camera-ready copy, this may or may not
be Word depending on your requirements. I have produced a good many books
with Word; some of them would probably have been "easier" in a page layout
application *if* I were comfortable with that app. Since my expertise is in
Word, however, I prefer to struggle with its occasional limitations than
face the learning curve (and expense) of using a different program.
