The book is a deep dive on paperless workflows for the Mac, iPad, and iPhone. It takes full advantage of iBooks Author and includes picture galleries, interactive images, movies, 32 screencasts, and nearly 27,000 words. There is over an hour and a half of video. Not only does this book tell you how to go paperless, it also shows you.
If you're not sure about the book or are like me and without an iPad right now, you can listen to episode 85 of Mac Power Users where David and Katie talk a bit more in depth about the paperless idea for Mac.