This is one of my favourite book clubs. It is a community of over a million and a half book lovers. It requires a signup. Once you are registered you can then connect to people who read what you post and also interact with what they publish.
2- Good Reads
This is also another book club that I am member of. What is cool about this website is that you decide upon titles and genres you like and Good Reads gives you insightful recommendations and right into your inbox. You can also join in discussions about books you or your friends read.
3- Shelfari
Shelfari is a community-powered encyclopedia for book lovers. It lets you create a virtual bookshelf, discover new books, connect with friends and learn more about your favourite books for free.
4- Biblionasium
5- Figment
Figment is a community where you can share your writing, connect with other readers, and discover new stories and authors.
6- Scholastic