I'm just getting started exploring the site and building up my bookcase, but I'm looking forward to discovering all kinds of neat things! With a free membership, you can track the books you're reading and would like to read. There are interviews with authors - well-known veteran authors like Karen Kingsbury and up-and-coming authors like Daniel Blackaby. There are book reviews (so I can make my "to read" list even longer!) and the books are arranged by genre which can be very helpful. There are community features and contests, and lots more!
It looks like you can connect with other users on the site as well. This link will take you to my profile page if you'd like to try that out! Kym's Novel Crossing profile