So you have a creative streak in you and you want to make a living out of it. You've always had family and friends complimenting you on how great you paint or how awesome your photography is. Your teachers in school always gave you an 'A' in the SUPW classes (socially useful productive work, they were basically 'art and craft' classes where embroidery, pottery, knitting and other forms of art were taught. It was a compulsory part of the course curriculum when I was in high school, don't know if it still is though.). And over the years you decide that you want to turn your avocation to your vocation.

But you don't really know where to start. 

Many obstacles stand in the way. Making art a full time career option means willing to invest a lot of money and time in advertising, developing prints, renting galleries to display your work etc. But now things have become a lot more easier for the modern day artist. Sites like deviantart.com, Flickr.com, gallerytoday.com, palleteartgallery.com among many others, allows one to showcase his or her work over the internet. These sites allows the viewers to order prints and review them as well. Rather than depending on an art dealer, the artist or rather the 'art entrepreneur' gets a good head start to his business. It gives him a platform where he can even discuss his work with people having the same interest.

Deviantart.com has over 11million members and receives some 100,000 submissions everyday. These include photography, paintings, digital art etc. The site also offers Creative Commons licenses to the artist so that he can decide how his work can be used. Flickr.com also plays host to a variety of photographers. There are also a few galleries like palleteartgallery.com and gallerytoday.com which caters to Indian art entrepreneurs only. 

To read up more on art galleries that made it big in 2009: http://www.theblogofinnocence.com/2009/08/best-online-art-stores-auctions-and.html