SITESMAIS

sketchpad.net um website que é uma boa fonte de tutoriais para o Adobe Photoshop e Illustrator.

Photoshop (Alguns exemplos):
Opening/Closing Paths
Modifying Paths / Points
Using Clipping Paths
Keyboard Shortcuts
Shortcut Examples
Pen Tutorial Templates
Pen Tips
Custom Textures 1
Custom Textures 2
Custom Textures 3
Tiling Textures 1
Tiling Textures 2
One-Pixel Brush Layer Basics 1
Layer Basics 2
Layer Basics 3
Layer Basics 4
Layer Basics 5
Layer Basics 6
Layer Basics 7
Layer Basics 8
Channel Basics 1
Channel Basics 2
Drop Shadows 1
Drop Shadows 2
Halo Text Effect 1
Halo Text Effect 2

Tutoriais tratamento de imagens:

Photoshop Levels Adjustment – Part 1
Photoshop Levels Adjustment – Part 2
Photoshop Levels Adjustment – Part 3

Illustrator (Alguns exemplos):

The Anatomy of a Vector Illustration – Part 1
The Anatomy of a Vector Illustration – Part 2
The Anatomy of a Vector Illustration – Part 3
The Anatomy of a Vector Illustration – Part 3A
The Anatomy of a Vector Illustration – Part 4
Working With Primitives
Keyboard Shortcuts For The Pen
Keyboard Shortcuts For The Pen – Examples
Practice Templates For Illustrator 7-9
Creating Multiple Page Documents in Illustrator
A Rainbow of Gel Buttons in Illustrator
Applying a Gradient Fill Across Multiple Objects