This page lists the free features of DeviantArt.Com which is the Internet's largest Art Community. I used to subscribe, but the free features are all I personally need.
Here are some of the basics they offer; (I'm sure I missed some),
* Hosting of your art in a digital photo gallery, in such a manor that it will receive a lot of attention and possibly comments if people like your art. All images are public.
* Chat with fellow artists in one of the many chat rooms.
* Read up on art news, vote on your favorite news, and write your own news.
* Write in your art blog.
* Share your art gallery / image gallery with friends.
* Search for art/images submitted by fellow artists. There is a massive archive of art sorted by category.
* Buy prints of the art you like. (And sell art, if you buy a subscription which has a lot of perks).
* Categorize your friends groups.
* Send and receive messages with other users, privately and or publicly.
* Meet fellow artists in your area.
* Participate in clubs, not just art related clubs.
* Download themes for your computer.
* Take part in contests with big prizes.
* Popular forums to talk about art and life in general.