What causes my 1998 Monte Carlo to not even turn over when I turn the key?

I deliver newspapers. Last night the car was fine, parked it at 5:30 am, then had to go for an appt at 8 am it would not start. But, it does not even turn over, it doesn't make a noise; no lights, no accessories. (Gas tank is at about three-quarters full.)

We tried to jump start it, but that didn't work. The cables sparked a little when we attached them to my battery, so it's probably not the battery. Also, this did not affect any change in my car, it did not turn over, nor did the lights or radio come on.

Is the problem electrical? or a fuse perhaps? I am totally broke so I need to know if it's something I can do or a friend with some moderate amount of knowledge, perhaps?