I find books work better than DVD's. Get them 1 at a time.
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Adobe Photoshop CS4 for Photographers : by Martin Evening
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Lynda Training.
Kelby Training.
Obviously the sky is the limit to how far you want to go. For basic editing, I'd recommend LightRoom, I believe it is a bit cheaper and is a bit faster when you have LOTs of images.
Photoshop Tutorials, Tips, Photoshop Cafe, free resource for Photoshop Users, Photoshop 7 to Photoshop CS4 and Lightroom. The ultimate Photoshop training is another good source for quick tips