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.
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.
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.
This is a platform where kids connect to their teachers, friends and parents to share and recommend their favourite books and good reads. It also provides books with different reading levels and has a great and intuitive reading logs.
Figment is a community where you can share your writing, connect with other readers, and discover new stories and authors.
Scholastic has a section in which teachers and students can share what they are reading and discover new books based on their friends recommendations.