Retroactive

You mention in your description on the project page that unless this module is enabled before groups are created that a lot of work must be done to update the database. I assume that means 'by hand'. If so, I would suggest a retroactive button to add the book pages for existing groups. I have added similar buttons to both og_forum and accounttypes modules that I maintain and it is quite nice, especially for people with existing sites that have just found your module. These kinds of functions usually are not hard to write.