The best thing to do would be to contact a local Realtor, experienced in your market, and ask them what other comparable homes in your subdivision are selling for. They should be able to provide you with a comparable market analysis and do a walk through of your home to point out some advantages or disadvantages you might have in selling. If you are just curious and do not want to go that far, you might try using http://www.homegain.com for a home value analysis.
Jason Ewing, GRI/CNS
Coldwell Banker Triad, Realtors