Old Coin Silver

How do I go about selling coins that are old? Like silver dollars, quarters, silver certificates.?
Have a friend that is looking to sell his old coins and silver certificates. How do I go about this without getting ripped off?
Lot depends on the quality of the coins. If they have a lot of wear then they are most likely more valuable as silver then as Old Coins. You would get the most by selling at a coin show if you want to sell the coins. A dealer will give you an estimate but be aware they want a profit also.
Of course you can sell them on Ebay.