2001 Mitsubishi Galant 4cyl. Where is the starter?

I'm having a problem with my '01 Galant. At first the car was leaking water into the floorboard on the passenger side, then after it stopped the heater and AC fan stopped working on any setting except 4. Then my car stereo speakers stopped working and now my car won't start. I try to turn it on and I get one loud click, then nothing. The headlights, taillights and interior lights all work as well as the lights on the dash and my car stero. I am totally lost as to what this all could be. I do know that the leak was probably caused by a backed up line from somewhere near my heater core, but would the water effect my stero and the ability to start the car? Also if it's the starter keeping me from starting the car then where can I locate it to give it a good tap with a screw driver?