My car won't start up

My car won't start up. I turn the key to the on position and nothing happens - no click indicating the solenoid is engauging, nothing. It started not turning over, and just clicking periodically these past few months, so I've suspected the starter motor going out. So now I'm trying to get to the starter so I can check the connections and clean them if necessary.

I understand it's under the intake manifold, on the drivers side near the radiator. I've been told I need to take off the engine cover to get to it, I've also been told I need to be under the vehicle to get to it. So how do I get to it? From under the car or above it? And if it's from under the car, do I need to remove the engine cover on the top?