Interested? Check out this site:
www.strategicbookmarketing.com
They offer services and/or lots of insight, including an article that gives advice about how to use facebook to market yourself and your book, using a profile, page and group:
http://strategicbookmarketing.com/FacebookExample.pdf
I’ve been on facebook for quite a while, but now have both an author page and group for my first book, Stromple and the Super-Huge Temper Tantrum.