Are there any lights on the dash, and it just does not crank.?
Possible Starter, relay or ignition switch problem. First check to see if you have a constant 12volts to the red wire at the starter terminal and also check to see if you are getting power to the dark green wire at the starter when the ignition is cranked.
Make sure your grounds are good, clean and tight, and then I would proceed to the previous steps in the last answer:
Auto Service Technician
ASE Master Technician. Foreign and Domestic