I recommend the Photoshop manual, and then lots and lots of practice/experimentation.

I know this is not the answer you really want (and it's unlikely to get the bounty ;) but it's my opinion (and I stress this is just an opinion) that tutorials will only teach you how to use certain steps to produce a certain result.

There is no substitute for learning everything the long way, finding out for yourself why to make a change rather than simply how. Training your eyes to analyse an image, learning when to trust your eyes and when to go by the numbers. Flexing your creativity. An experienced Photoshop artist will be able to look at any tutorial end image, take the source images and recreate it, probably using different steps to get the same result. There are so many tutorials that promise instant results and I can see the appeal, but this ability to me is far more valuable.