2002 Kia Spectra No electrical power at all.

This morning, when trying to start my car, I noticed that turning the ignition key did absolutely nothing. I then noticed that the car seemed to not have any electrical power at all. No lights, no digital odometer, no radio, no power windows. Nothing.

I tried to jump the car, assuming that the battery had died (though I just replaced it about 18 months ago, and Reno isn't really an extreme climate.) This attempt did nothing - again, no power whatsoever.

I checked all of the fuses - they are all in good shape. A fried suggested that perhaps the "power inverter" is the problem, but all my google searching have not been able to help me identify what that part is. The car cannot be disengaged from 'Park' - so I can't even move the car at the moment.

I think my next step will be to get a multimeter and try and test to find if there is a short (which I'm guessing is the problem). I'm somewhat of a novice at car repair, but I can't really afford to take the car to a mechanic (hence, I'm driving a 2002 Kia Spectra).

What should my next course of action be?