Lightroom is far and away the best photo-editing and -organizing software that I've seen (and I've tried a lot of them), and this book is a rock-solid overview of how to use it.

Scott Kelby's guide is, as usual (and I have read a half-dozen of them), the best way to cut through the mass of features in any photo software and get to a workflow that makes the best use of its capabilities. I would have liked a little more depth on the features that are new to Lightroom 3, but I extracted enough that I feel confident using the new software.