Link your swap here. LINKS ONLY no actual products. Please do not list more than once.
Don't forget to add the link to your signature. Click on your username at the top right, scroll down to signatures then Edit. At the bottom of the popup will be a "Show Your Stuff" and look for your trade listing.
Sleepykat has a suggestion which I'm passing along.
Update: The way the settings are for the site is that members have about one day to edit their own posts and after that the edit ability goes away. Go ahead and re-add your url with a note that your trade post has been updated. :D