I know these guys are pretty good. Here are a few links to their site for you.
Selling your home:
Here are some listings in the area you mentioned (37421):
I believe Ron's answer below is correct regarding Trulia.
There are other online sites that are available that are no or minimal cost to list your property. The best exposure would be to work with a local real estate agent to get your property on the Multiple Listing Service "MLS".
Let me know the details of your home as a "for sale by owner" in case I have buyer looking for a home in your area.
If I may help in any way please let me know.
Teresa Scheiwe, REALTOR
Licensed in TN and GA
Area MLS listings updated daily~ ISellChattanooga.com
"I Want to Provide You the Best Service!"