So, this is pretty simple. You can google it, but since we seem to "google" on this forum before on the actual net, figured I would put it on here. Now most toggle switches now come lighted, so you could skip the "indicator light". And you can replace the "fog/driving lights" for anything that you are hooking up. Enjoy.
Just to add to this. If your using a 20 amp fuse. I would use a 30 amp relay and if up the fuse amp to 30 then up your relay to 40 amps. This way if it happens to blow the fuse your not worried that it blows the relay as well. Here is a link for a general purpose 12 volt DC 30 amp relay. http://www.opentip.com/Electronics-Computers/Amp-Bosch-Relay-p-878391.html