I have all three of those, plus one more by Katrin Eismann for working with old photographs. The Kelby book is the newest, and it has some excellent things in it. Aaland is still one of my favorites, although I never bought the update for Elements version 2. Lynch is more advanced, but it definitely covers things not addressed by either Aaland or Kelby, plus the CD includes some additional tools that are extremely useful. You wouldn't go "wrong" with any of them, but if you're only going to get one, I think I'd recommend Kelby. My personal opinion, of course.