Artportal Resources for Artists
Artist Communities
Artists Unite Issue
CGSociety (Computer Graphics Society)
d'ART - Artists' marketplace, community and forum
deviantART - Mainly for digital artists. Display your art & hang out in the forum.
Kara Art
Saatchi Gallery, London

Artist Forums
ArtConversation - Not specifically geared to artists, but artists are welcome to post links to their websites in the "My Art" forum.
eBay Art & Artists Forum - Appears to be populated mainly by artists who sell their own work through eBay.

Art Biz Blog - Alyson B. Stanfield
Art Business Thoughts - Articles for Artists
The Art List - Art Contests, Competitions and Opportunities for Visual Artists and Photographers
The Artist's Magazine    The Artist's Magazine Blog
Incredible Art department - Art Careers and Jobs in the Visual Arts
SELLOUT - a dialogue about every practical aspect of being a visual artist