
“This tutorial will teach you how to create a shder which makes any objects you applied it to, look like its a cartoon. It’s easy to get a Toon look just in minutes. Even though it’s that easy you do need to keep in mind a few rules. Never do your image character too dark. Black is not a color for you. Even the dark blues of night would look better, believe me.”
http://www.3dtotal.com/team/Tutorials/toon_shader/toon_01.php