ArtKids Rule!
Links to many good tutorials for animation, art appreciation, ceramics, drawing, magic, painting, pastels, performance, photography, printmaking, sculpture, and writing. Also includes lesson plans and reference links.
Artshow.com
Very nice site. Tutorials and galleries for painting, drawing, photo/digital, sculpture, printmaking, pastels, and ceramics.
Creativity-Portal.com
A huge directory of everything arts & crafts. Links to supplies and tutorials.
Gurney Journey
Amazing blog from master artist James Gurney, creator of the Dinotopia books.
Laurie McCanna's Free Art Site
Web graphics, Photoshop tutorials, clip art.
Pigments and their Chemical and artistic properties
Excellent site!
Portrait-artist.org
An excellent resource for aspiring portrait artists. Tutorials, demonstrations.