If you're comfortable with it, and live in the states, Craigslist isn't a bad place to sell components. Just be sure to include a couple of photos, and what I do, is meet people in a neutral location with a lot of traffic (grocery store parking lot, etc) and always do the transaction with cash.
The best thing you can do price-wise is to post the ad online with all of the parts, and have the users set the price. There are people out there who have surprised me by paying for parts several times the amount I was going to price it at. So don't lock potential buyers into a price, let them set it, and go with the one who offers the most.
If you don't want to take the Craigslist route, you can try to sell the parts on EBay, but their fees can be a little high at times (especially when you start adding more photos). Best bet is Craigslist if you want to offload the parts quickly. Folks like myself scour CL on a regular basis looking for components.
If you're not in the USA... bummer! Not sure what to suggest then