What kind of art? Do you know if it is rare, or are you guessing?

If you are new at this, the first step is to try and identify as closely as possible. Artist, provenance, style, etc. Look for marks, names, labels. Many things have high values that, unless you know something about them, would not be guessed correctly. An early baseball card cound be worth up to $30,000 or so. One of those large carnival paintings on canvas may be worth $15,000 or so, if by the right painter.
Much can be done on a net search. There are a number of sites selling antiques, ceramics, etc., and some auction houses list the prices obtained at their last sales. Look and compare with what you have.
For some things like watches, Ebay is a first stop. Even for oriental ceramics- a civil servant put the ceramics and other items collected in China some years back with an auctioneer in Toronto area, in turn this auctioneer put the items on Ebay with good photos and descriptions. One vase sold for $28,000 and several items in the $1000-3000 range. Good auctioneers send notice of special items all over.
For jewelry, go to the better dealers in town. Many will help.

Go to a local appraiser- auctioneer, and get an appraisal. If he doesn't know, he can recommend someone who does.
(Recently, a painting placed with a local, reputable, auctioneer sold for over $500,000. The auctioneer's art auctions are put on the net, and bids can come from all over, not just locally).

Finally, don't hurry.

I no longer collect, but I know a wee bit about southwestern and Indian art, Canadian art, other paintings, ceramics, stamps and watches and could possibly point in the right direction. PM.