steering wheel won't turn help!!!

i have had a "knocking noise" in my engine when the car is in park or sitting at a stop light. we listened to the motor and thought that maybe it was the alternator going out. well today i went somewhere and was parking and the car died. however when i turned the key the windows etc still had power. when i kept trying to start it there was a loud whining noise but eventually i got it to start. well when it started a bunch of smoke came out of the engine area for a few minutes, then it stopped and the car was idling normally, not smoking, but when i put it in drive to move the steering wheel was impossible to turn. is this the power steering belt or the pump? help me!!!!