Any character you can trade with will buy whatever you want to sell. But keep in mind that only vendors will have plenty of gold to trade your items for, most other characters only have small amounts of gold (or none at all). You can find vendors in most towns (including Cyseal, approximately in the middle of the town).
To trade for gold, simply select the items you want to sell, and click the little icon (with the scales) in the top middle of the trade window. This will automatically choose the correct amount of gold from the vendor's stash.
If you decide to trade/sell your items for less than they are worth, you'll gain "attidude points" with that vendor. I'm not sure if this has any advantages later on (for example more gold for items).
Last edited by RiptoR; 03/07/14 11:27 AM.