Yea, just use Craigslist... here in Canada, I use Kijiji which is just like Craigslist.
I recently sold my computer (last week) through Kijiji. Just be careful to not fall into any tricks into scam and such. Always invite them to a place where it is acccessible to both parties, lots of people (like infront of a coffee shop or something), etc etc..
I tend not to part out individual components because it's such a hassle...