Joseywales,
I will throw out a couple of possibilities:
If they are high-end collectibles, civil war era, militaria, or stuff like Pythons, James Julia Auctions specializes in guns and other collectibles. They are in Maine, but travel all over the country, too.
Their home page:
http://jamesdjulia.com/division/gun/You can get an idea of the quality of merchandise by looking at these lists for the next auction there.
Their current listing for an auction March 14 & 15 - part one - 759 items:
http://jamesdjulia.com/auction/391-spectacular-auction-of-quality-arms/?session=1 The listing for the second lot - 687 items so far:
http://jamesdjulia.com/auction/391-spectacular-auction-of-quality-arms/?session=2Otherwise, for single guns, this forum, Ruger, etc. and the gun shows or Gunbroker (better than any of the others, IMO) in spite of their warts.
Other auction options include Rock Island as suggested by raamw, or one that I have followed somewhat to see the quality of their merchandise and the prices they get:
Gunrunnerauctions.com, in Burton, Ohio (south east of Cleveland)
They seem to auction about 200 every month, and they will take a collection and sell it as they get to it. They get some really nice collectible and high-end guns, and get some pretty good prices for them.
I would suggest watching the auctions on Gunrunner and maybe Rock Island to track the quality and pricing for a while.
Myron
Edit to add:
The LAST thing I would do is bundle them up and take them to your local friendly gun store. This is a sure way to get the least out of them.