Graphic Artists Guild
National Artist's Organization
James Gurney's fantastic blog. The Dinotopia creator has a wealth of painting and illustration info here. Highly recommended!
Website for Dan Zimmer's class act magazine. I get more out of this publication than any of the Society of Illustrator's annuals.
David Apatoff's very insightful blog on the art of illustration.
Leif Peng's awesome blog that truly is an inspiration to me every time I visit it! Chock full of images and info regarding the great illustration and illustrator's from "back in the day."