The best way that I know of to figure out current market pricing (I'm sad to say it's down from years past now days), and also a great way to sell your guns, is to look at
www.Gunbroker.com and
www.gunsamerica.com for the same model guns in the same type condition as the ones your thinking of selling. I have told my wife to list any of mine (that my kids don't want) starting at 75% of what I think they "should" bring and let the auction do it's thing (bidding wars we hope!) to bring what their worth at that time.
I'm sure that if you list here what you have we can give you some ballpark prices that could get you started.
Tips listing your guns:
-include good pictures
-point out any imperfections in the add
-don't include why your selling them (brokers will swamp you)
-include any shipping cost in your asking price (people like to think there getting FREE shipping
-if its a specialty gun there are LOTS of specialty gun forums on the net, find a forum for that gun and list it there
I'm sure others will think of more.