I'm a member of IAntiqueOnline, a community for learning about, how to buy, how to sell, and sharing stories about your antiques and collectibles. With 6500 members and growing, they are now branching out to include fine art. Here's a quote from the editor, C. Dianne Zweig:
"Wanted: More Artists To Join Our Community And Share Their Paintings, Drawings, Assemblage ETC.
If you are an artist or know other artists, please tell them that IAO is a great place for them to promote their artwork. We welcome artists to come aboard and start more groups about art. We also will feature original artwork on our main page slide show. So if you know any artists out there...tell them that now is the time to build a Profile Page on our site and to share their artwork with others. We will help them promote their art."
The site is completely free, so fine artists - give it a try!