Goodreads - See what your friends are reading.
Litsy - Where books make friends.
LibraryThing - A home for your books.
Reedsy - Reedsy is a complete book publishing platform with an elegant, collaborative online editor.
BookSloth - Book Sloth lets you add books, post and see reviews as well as interact with other readers.
BookAuthority - BookAuthority collects the most recommended books on business, technology and science - as featured on CNN, Inc and Forbes