Having lights and radio dosent necessarily mean that your battery is good....you could have it load tested just to be sure it hasn't been damaged...

If the car is cranking over and not starting you should check the Crankshaft Position Sensor...

Crank and no start is usually the Crankshaft Position Sensor(easy fix and costs about $70)

No crank and no start(duh!) is frequently the Relay Control Module (bad solder joints that you can fix)