I really like Real World Photoshop CS2 from
Peachpit Press it assumes you know the basics and then takes quite a deep look at some topics that would be close to the photographer's heart. It was written by Bruce Fraser and David Blatner who, like Scott Kelby are recognised experts in this area. (there's a review on my website, not sure if I should mention that here
)
I'd also recommend Real World Camera Raw from the same series for anyone who's struggling to get the best from their raw files (it deals with ACR but a lot of the background info is relevant to any raw image / converter). I shall be looking for an updated version of this that covers the new options in ACR3.0 / Lightroom.
Finally, if you've got a stack of old photos from Great Granny that are creased and faded and need fixing up Photographic Restoration and Retouching by Karen Eismann is absolutely excellent. It's got lots of real, practical, detailed and well explained methods for dealing with tears, rips, colour issue etc. well worth a read if that's what you're into.
cheers
Dan