K Michael Russell (videos) - Tons of photoshop colouring tutorials including flatting, layering , brush customization and more

Representing Emotion with Colour (video) - Strip Panel Naked

Coloring Guide (picture) - Bleeding Cool

Understanding Color (video) - Blender Guru

How to Color Inked Line Art in Photoshop - WebpageFX

Colours are the first thing anyone notices when they look at a page. They’re also very easy to get wrong.

Just like drawing, I’m NOT going to teach you how to colour. What I WILL do, is show you the tools and techniques you can use to maximize what you can get from your colours.