I strongly recommend anything by Scott Kelby.
http://www.amazon.ca/Adobe-Photoshop...0422142&sr=1-4
He writes in a very non-technical way and his usage of imagery in his teaching is top notch. The writing is never boring and he cuts to the chase.
If you're looking for real top-tier learning from professionals online, he also has
http://www.kelbytraining.com/
It's a little more in-depth and doesn't just cover photoshop, but some of the resources available are fantastic.
If anybody is looking to take their digital photography to the next level, his 3-book "The Digital Photography Book" series is outstanding.