As a fringe onlooker at the publishing business, I would caution that the pros do not do book editing in .pdf files. The "editing" that can be done directly to .pdfs is generally of the sort used to exchange comments about the book, but making layout changes directly in the .pdf is both clumsy and unreliable.

Your book should be prepared in a "proper" text/layout program, probably one you already have. When you have the "editing done" you create a .pdf to assure portability and consistency of appearance for your users; but your file in the layout program should remain your "master file."

For a simple book, Word is more than sufficient. For a "trivial" or "flash" book - where appearance is more important than content - something like Project or Publisher might do. For something complex or with a really fussy editor, you'd want Pagemaker, Quark, Framemaker, etc.

Even for a minor edit to the book itself, the preference would be to correct the "master" and then simply regenerate a complete new .pdf.

But that's just one observers opinion...

John