I hype this site pretty often - it's an e-mail book club (actually, a dozen of them, and you can sign up for as many as you want) that makes weekly selections and e-mails you daily excerpts. It's a convenient way to sample books, and I've found a lot I wanted to read further after getting that taste.
Our book club tends to be a social gathering as much as a discussion group. Usually each meeting entails wine, food and, of course, the book. So we coordinate our reading, our food, wine all through Qlubb. It's just an easy way to manage each meeting and attendance. It's super easy and free.
A free, worldwide membership community with the goal of "making the whole world a library." Register the books you read and pass them along - you can follow their travels through their BCID numbers. Set your books free, and find new ones for free, too!