Most meteorites have a dark fusion crust. Some have divets that are called thumb prints. The first thing to check is if the rock will attract a magnet, most have a high iron content.
If an of the above are present take it to a university or planetarium and if it is actually a meteorite they can confirm and will probably make you a offer to purchase it. A couple of years ago a fellow here found a meteorite about the size of a grapefruit and took it to the planetarium and they gave him $10,000.00 on the spot and it now is on display in their museum.
A good place to get some info. on meteorites is from a company named (I believe it is) Bethel Sciences, you can find their ads in Sky and Telescope magazine and in Astronomy Magazine, call them and ask them to send you a copy of their catalog, there is a lot of useful info. there.
Clear skies,
Starman