Assignment photography (architectural) is my main source of income, but I have sold quite a few prints in the past few years. The first sales were to friends, then a client bought a number of images of Washington, D.C. for an installation in a residential building. Since my book came out last year I have sold a few more. Now, that I wrote all of that, I would say selling prints depends on your expectations.
First, is your work strong, would someone want to buy it? Flattery from friends is nice, greenbacks are better.
Second, you can't sell your prints if you are shy about it. Be willing to talk about your work when someone expresses an interest - and for God's sake do NOT show images on a phone or small tablet. Make an impression with the biggest image you can. I would recommend picking 6 of your strongest images and printing 13X19 samples to show. It isn't a large print for a wall, but held in hand as a sample it is quite impressive.
Third - The biggest problem for those new to selling prints is pricing. "How do I put a value on my work?" The short answer is, you can't, the market place does, but you have to start somewhere. If you do build a good reputation, pricing will be easier. In one of the previous replies I think someone said you have to make money. That is true. A lot of this depends on where you are trying to sell, the demographics of the area (income, etc). The same print in one market may only get $200 and in another market $2,000. So, if you live in a middle-income market, you are going to most likely sell on the lower end, which means you have to produce your prints at a modest price. If you are not printing yourself, use a company like Adoramapix. You can make a 12X18 print for about ten bucks. On the high end, a lab like Bay Photo will make fine art prints in that size for $47.00. Assuming, when starting out, you want to mark the print up 4X (don't forget you have the cost of your gear and time to compensate for) the Adoramapix print can sell for $40 and the high end fine art print $188. Again, what your market will bear is very important.
Manyf people advocate the use of social media to market. I can tell you that with 2 web sites, Facebook, Twitter and LinkedIn (since dropped), I saw very little return. There is the distinct possibility that I am not doing social media properly, after all, I am a geezer in this business. Most of my sales now come by word of mouth. I hope this helps.