collection of technical articles found on the web that can be useful
One interesting way to represent liquids in a grid based world, is to use a form of cellular automaton. In this simulation, the cells attempt to disperse their liquid into their neighboring cells.
Marching Squares is a family of algorithms for automation that appear in everything from isolating isobars on weather graphs to selecting shape outlines in image editors, and even generating game worlds.
A very popular art tutorial with all the basic concepts like matarial, shadows, perspective with easy to understand hand-drawn pictures.