23 Creative Book Cover Designs and Their Story
Another great post from 1WD.co
http://www.1stwebdesigner.com/inspiration/creative-book-cover-story/
Update, here are two more great showcase / round-ups of cool book covers:
http://designresourcebox.com/inspirational-showcase-of-book-cover-designs/
http://www.1stwebdesigner.com/inspiration/beautiful-book-cover-design/