To begin your online search, type in "selling blank online" into a search engine. "Blank" should be filled with the type of art you are selling, whether it is photography, paintings or sculptures. As you go through these sites, be sure to read the terms of agreement of each one. This is where sites will list any fees they charge for displaying your artwork.
Once you have uploaded pictures of your artwork, the next important step is picking the best possible keywords to use in your description. This is called search engine optimization, and it can be used to help potential buyers find you and your work. Let's say you are trying to sell a painting of a sun setting over a waterfall. It is important to think like buyers and what they might type into their search engine. Most likely they would type words such as "sun," "waterfall" and "sunset." Make sure you include these words in your artwork description.
Advertise your site as much as possible. If you don't have the money for paid advertisements, find creative ways to get the word out. Search for art blogs and leave comments on posts with a link to your art page. With as many art blogs as there are on the Internet, you could be driving a lot of traffic to your art page.