To understand the potential customers in any area, my first stop is the free online resource from Claritas and Nielsen. Their Zipcode Lookup tool is awesome!

Allow me to demonstrate.
1. Go to page. Type in zipcode of interest. For this case, I’ll use my own 39571.
2. I receive a list of the market segments. By clicking on their name, I’m sent to a page that provides a bit on that segment.

Big Sky Families
Upper-Mid Middle Age w/ Kids
Scattered in placid towns across the American heartland, Big Sky Families is a segment of middle age rural families who have turned high school educations and blue-collar jobs into busy, upper-middle-class lifestyles. Residents enjoy baseball, basketball, and volleyball, as well as fishing, hunting, and horseback riding. To entertain their sprawling families, they buy virtually every piece of sporting equipment on the market.

The page goes on to list other key details like they order on ebay and read Field & Stream. So now I have a potential sales channel if I want to market to more of this consumer segment nationally and a good place to advertise to reach this audience.
Another stop is the local Chamber of Commerce site and the economic development council. Many of these groups have a website area that provides demographic details from a business perspective.

Another initial key step in digging into a local area is reviewing the media/advertising kits of local publications. Local newspapers and magazines provide statistics on their readership.

These three places are great starting points for learning more about a local marketplace.