This was done by user jason_maranto at conceptart.org. Very helpful in trying to determine values for the sake of composition and not always what seems scientific. Analyzes the works of Frazetta as well.
Daarken is a concept artist working on Warhammer Online who does tutorials in his free time. He sheds light more on Photoshop techniques than art fundamentals, though it's awesome nonetheless.
Lin Ran's tutorials translated by a user in conceptart. Lin is just godly at painting. I found it revolutionary in how to perceive colours through RGB rather than the usual HSB because the world ultimately works around light reaching our eyes. One of the best free tutorials I've ever read.
A little treat for people who actually decides to click "Alexander Chow" on the Animation blog list :) . Now to cram for today's storyboarding test...