Here you can find past articles I've written, broken down by category.
Photoshop Specific:
Photoshop CS5 Mixer Brush Tips and Tricks
More Photoshop CS5 Mixer Brush Tips
Selecting a True Neutral Gray in Photoshop for 16-bit Image Layer Modes
Digital Painting in General:
Copic Color Swatches for Photoshop (and Manga Studio)
Choosing Real Paint Colors for Painting Digitally
Real Media Paint Swatches
Using Traditional Painting Techniques Digitally
Selfridge's!
Hardware:
Wacom Cintiq Tips and Suggesions
Animation:
Stop-Motion Animation Primer Part I: Cameras
Stop-Motion Animation Primer Part II: Software
Blogger:
Upload Original Size JPEGs to Blogger