The first one is to obtain a voltage tester and insert it in either of the vertical slots. The round one is a ground and we will tell you how to test that in a bit. If the voltage tester lights up or beeps then you have power there. It is a good idea to test the outlet even though you shut off the breaker. Who knows you may have turned off the wrong breaker!
To test the ground on a three-prong outlet get a neon test light and insert one end in the ground and the other end in both of the vertical slots (be sure to touch the safe insulated part of the tester) of the outlet. If you get a bright light each time then you have a good ground.
To find the hot wire in an outlet box first turn off the breaker to the outlet, test it to make sure it is still not live like in the first paragraph, then unscrew the cover and box and pull from the wall. Next, make sure that the wires are separated and turn the power back on. The last thing to do is get an inductive voltage detector and hold it close to each wire and if the detector lights up then you have the hot wire.
Things you may need: