There should be plenty of black cables running around with these funny looking plugs on the the end. As the name implies all you need to do is twist them to lock them in place. If you ever need to get more plugs, you need 15A inwards tab twist-lok plugs.
There is also one cable with a regular three prong plug at one end, a dimmer switch, and a twistlok female at the other end. You can use this cable to test the lights before you put them up. This will be useful because it is much easier to replace the bulbs on the ground than in the air.