Small Engines (Lawn Mowers, etc.): riding mower, briggs and stratton, riding lawnmower

Question
I have a murray riding lawnmower that I think the starter is shot. when I try to start the mower with the key you hear a spinning, like its not getting any fire. Or could it be the solenoid. If so I need to know how to replace it. any help will be greatful

Answer
First thing I would start with is the battery cable ends.  Dis-connect and clean the battery terminals and battery posts with a wirebrush.  

Second thing I would do is check the starter gear to make sure it is not stripped.  

Do you know if you have a Briggs and Stratton engine?

Eric