The article below from Mashable suggests you do some basic one on one research before trying to leverage social media for a small business (you know like a dental practice). In dentistry we have some other options not available to most other small businesses. That is companies set up to act as our dedicated IT online managers. My first choice is Sesame Communications.
The list of social networks and social media tools goes on and on, and as a small business owner, the biggest limitation you’ll run up against when planning to use social media is not likely going to be cost, but time. Utilizing social networks and web tools properly requires a significant time investment, both for learning how to use the networks and setting them up, as well as maintaining an active presence and building a community.