If you haven't purchased Paperless and you have even the slightest interest in reducing the amount of paper in your life, you should get this book. David Sparks, the author, explains it as:
Paperless takes the mystery (and fear) out of going paperless with your Apple technology. The book includes 32 screencasts, 4 movies, over 26,000 words, and other rich-media assets to turn you into a paperless ninja.
It was named one of the Best Books of 2012 by the iBookstore and it certainly deserves it. David is very good at explaining things in a very straightforward and approachable way. It's also a great showcase for books made with iBooks Author.
Paperless is usually $10, but it's on sale at only $7 until December 31.