Is your coolant level low?
Check for leaks when your engine is hot & cold?
Does it smell sweet?
Do your radiator fans turn on?
(With your motor off, turn the ignition to the 'ON' position & turn your AC on. You should here the fans turn on.
If they don't, check the connection for the fans (which is right by the fans)
Check the fuse to the radiator fans.
Your thermostat may be busted (maybe)