The first thing you need to get is an 9, 12 or 18 volt AC/DC adapter from an old phone, transistor radio, or something like that. The higher the voltage the better.
We found an 18 volt adapter at a thrift store for two dollars. Maybe you have one laying around in a drawer in your house somewhere.
Cut off the small plug at the other end of your adapter, and separate the wires. Strip the ends and attach an alligator clip to each wire with the screws that are supplied.
You can find alligator clips at a local hardware store or WALMART.
Don't buy the copper colored ones!!!