To write a Genealogy book, I highly recommend that you buy one of the genealogy software packages that has a book-making feature. I have used Family Tree Maker (now using 2011) and its book-making feature is excellent. (I do not work for FTM or Ancestry.com.)
One thing to consider is that, basically, there is only one reason to print a genealogy book. That is to share your research with people who do not have a computer - - - and in that case, you don't need to give them all the information you have in your genealogy computer database. Here is an outline I have used to construct a paper book for a specific relative (called the "Primary" person below):
* Cover page (title, coat of arms, origin of family name, author, etc.)
* Table of Contents
* For the Primary Person
* An ancestry chart for Grandfather A
* An ancestry chart for Grandmother A
* An ancestry chart for Grandfather B
* An ancestry chart for Grandmother B
* For each other person (typically 8-12) included in the book:
* An hourglass chart which shows that person's parents, children, and siblings (typcially only 1 page)
* An individual reports showing facts, notes, and sources. (typcially only 1 page)
* A page with small images of documents, photes, & pictures
* An Index of people references in the book.
These contents result in a book about 50-60 pages.
One of the great advantages of this approach of using FTM is that when I add/correct facts in my genealogy database, the book is updated automatically. (This automatic updating even happens on text pages I created as a historical story about the person.)
Finally, once the book is completed in electronic form, I sometimes upload it to a web site that professionally produces books. I have them made with a spiral binding, a heavier paper cover, in color, and the size is 8 1/2 by 11. The cost per book is about $20. It would be less than $10 if only black and white.
I hope this helps.