Here are a few good sites for you to look at as far as selling it via an auction or online sale
Sedo is a site that will sell your domain name
http://www.sedo.com/services/s_selldomain.php3
You can also sell your domain through Digital Point Forums
http://forums.digitalpoint.com/forumdisplay.php?f=59
This is a forum with some ideas on how you can sell your domain name
http://forums.digitalpoint.com/forumdisplay.php?f=45
You could also try and sell it on http://www.eBay.com
Depending on the name of the domain, you could sell it to the owner of the .net or .org version if either of those are registered.
You could sell it directly to someone, like if you have a domain that is the name of someone's company or related to a company, you could market it directly to them, thought it is a bit harder.
If you do sell it directly to someone, it might be a good idea to use a company like http://www.escrow.com to insure that you get the money and they get the domain name and it is all fair and everything checks out. Thou, the price of the domain name might not warrant the escrow fees associated with the transaction if you do use them.
good luck selling your domain name :)




