ok, i cant get my car to start right now and i need to go to work.i turn the key and nothing happens. what can i check?

 

No sound at all? Could be the solenoid. Push the horn. Anything? If no horn then dead battery. If horn sounds then I'd say solenoid and you can jump the terminals. If battery then you (and a friend) can push start it if a manual tranny. Good luck.

 

If it does nothing as in no click or anything, check your battery connections both at the battery, the solenoid connections on the firewall, and finally your ground wires.

 

horn works. but still wont start. i think im gonna take the day off to fix this. what do i need to buy/repair?

 

probably a starter solenoid then. Quick way to test that is to do what CanonBall suggested. Short across the two copper terminals on the solenoid and see if it starts up. If it does. Replace the solenoid. $10-13 at teh local auto parts store.

Use a plastic handled screwdriver and do NOT touch the car when you touch the screwdriver to both terminals.