The iPhone is only sold for a couple of hours and already there is a book called "The Missing Manual". Strange, but it should be good since it is from O'Reilly Media

As you'd expect of Apple, the iPhone is gorgeous. iPhone: The Missing Manual is a book as breathtaking as its subject. Teeming with high-quality color graphics, each custom designed page helps you accomplish specific tasks -- everything from Web browsing to watching videos. Written by New York Times columnist and Missing Manual series creator David Pogue, this book shows you how to get the most out of your new Apple iPhone.