This first part is pretty obvious, I have a long list of such names, but I'm not sure how to go about an actual sale, the auction sounds like a good idea, thank you!

Look for the email I just sent you if you're interested in trying to get it auctioned off.

Could you tell me too, please? A friend of mine has asked me to help him sell a three character .com domain name and I don't know how. What do you think it would go for?

I know that Moniker does this exact kind of auctions. You could just start at http://domainauctions.moniker.com/how_to_sell and try to find them through their website. Or email my user name at gmail.com and I can ask internally (they are owned by the same company that owns my employer) for who you can get in contact with there behind the scenes. Of course I may be told that people are supposed to go through the website, though that is less likely if the domain name is a really good one. :-)

Thank you!