I'm NOT undermining anything Pizzaguy is recommending and I like the post above from amx1397.
I am wondering if your siren works when you push the red panic button on your FOB. If you get no loud siren then you should try to start your car with fuse #9 removed. It is a quick easy thing to try and cost nothing. Remove the negative battery cable, remove fuse #9 from the box under the hood and wait a couple minutes before re-attaching the battery cable. Then try to start your car. Could be that a bad siren has fed back into the anti theft system and is preventing the car from starting.

Unlock your doors with the FOB before you disconnect anything. If your still in the same no start situation after trying the fuse 9 removal, just put it back and continue trouble shooting.