Goodreads - See what your friends are reading.
Four Hour Book Club - 300+ Books recommended on the Tim Ferriss Show 📚
LibraryThing - A home for your books.
DevFreeBooks - A collection of free books for developers
BookAuthority - BookAuthority collects the most recommended books on business, technology and science - as featured on CNN, Inc and Forbes
Top Startup Books - A collection of must-read books for startup founders.