There are many places on the Internet now that you can list your domains for sale or buy them.  Some charge a listing fee and some don't.  Some charge only to be listed at the top of the page or boldly.  Some charge a percentage to the buyer or seller.

        There isn't much to say about them except that you should read the terms and conditions of listing carefully before you list with them.  Many of the sites out there that call themselves brokers, I will list here unless I see better evidence that they are providing actual brokerage.