Bookshare - I'm giving away my books
Goodreads - See what your friends are reading.
Bookself - The social reading app 📚💬
LibraryThing - A home for your books.
24-Hour Bookclub - Every few months, we pick a book and read it in one day.
BookAuthority - BookAuthority collects the most recommended books on business, technology and science - as featured on CNN, Inc and Forbes