If you're new to Photoshop or Illustrator, start here. These tutorials provide step-by-step instructions specially written for "newbz." Once you understand the fundamentals, you'll be prepared to venture into the tougher neck of the woods (metaphorically speaking).
So you know the basics, but you aren't quite ready for the big leagues. The intermediate tutorials will help you hone your skills and prepare you for more advanced techniques.
You understand the principles of masking, non-destructive filters, alpha channels, and blending modes. Now you're ready for the good stuff. The advanced section of tutorials offers you a plethora of crazy cool techniques to help take your skillset to the next level.
Uber Advanced Tutorials
When it comes to Photoshop or Illustrator, there's not much that you can't do. In fact, you've given up on online tutorials because they're all just too basic. Enter the uber advanced tutorials. Here you'll find things that would make a rookie whimper. The force is with you. Now become a Jedi.