I'm not an electrician, and, with my house being considered "old construction", it's hard to get an actual electrician to come in and look at the wiring. After successfully installing my garbage disposal, I still had to figure out how to wire the outlet and the corresponding switch. The garbage disposal would run when the switch was OFF, but, when I turned the switch ON, the breaker would trip.
There were two pairs of wires in the outlet box. Using a digital multimeter, I found that one pair was hot, while the other was not. I took the black wire with power and wire-nutted it to the white wire that had corresponded to it. I then took the remaining black wire, put it on the brass screw of the outlet and put the white wire on the gold one. When I re-activated the circuit and flipped the switch, I heard the sweet hum of whirring blades chopping up left over beanie-weanies.
It was nice to have a little success with wiring the garbage disposal. And, now, it's time to move on to getting my dishwasher installed. We'll see how it goes.