I probably should have put this one as the first place to advertise your book. http://www.goodreads.com. Has a lot going on for writers on their website. First you must join for free as a member who reads books. They will ask for ten books you have read and have you rate them.
You can also import your friends from Facebook and Twitter and see what they have been reading.
After waiting for a day, you can submit your book into their data base. From there you can join groups. The first one I joined is called Pure Indie Promotion. This group encourages you to promote your book to others and let them know about promotions.
Amazon just acquired Good Reads, so it’s another good reason to join.
What I’ve written here really only touches the basics of what you can do on Good Reads. So off with you now and get promoting.