I lucked out for my project. I know two licensed electricians, so I just asked a bunch of questions. Everything checked out okay too, and all it cost me was a 12-pack of Sam Adams Octoberfest.
Funny, my compressor runs far more efficiently in it's new home than it did at the place we were renting. I think my wiring must be better than the stuff there.
obDisclaimer:
But yes, if you don't know what you're doing, you should either have access to a licensed electrician, or get one to do it for you.