Goodreads is a community designed to bring together books and readers. When you set up a profile, they will ask you what kinds of books you like. Then their program gives you lists and descriptions of other books you will probably like too. It's the perfect way to answer the question, "What should I read next?" Not only do you have books to choose from, but most of the books will have starred reviews, much like Amazon. So you can know what other people's opinions were as well. If you explore the 'find friends' option, you can make a list of friends from Facebook and Twitter who are on Goodreads as well. Then you can recommend books to friends and they can recommend books to you. There are also forums where specific books are discussed, as well as the writing process, certain authors, and pretty much anything related to writing can be talked about.
If you are an author with a book (with an ISBN), you can create a dashboard with your information, and list any book you have written simply by typing in the ISBN. You might even have Goodreads reviews of your book and not even know it! Goodreads has all kinds of writer's resources, including a community of writers open to give helpful answers and advice.
Goodreads also offers a contest program for any author who wishes to participate. You can offer a certain number of your books to give away, and people can sign up. After the given time, you must send the giveaway copies to the winners (randomly chosen by Goodreads.) This is a good way to church up interest in a book. My first book contest generated over 700 entries, and I received one review from giving away two books. Not a bad investment for almost free advertising.
Have you posted a Goodreads contest? Did you find it helpful? I would love to hear any thoughts you have about Goodreads in general. Happy writing!