Your switch has three wires, yes?
If you live in Vermont then 12v constant is the way to go.
For those of us in the desert, switched 12v is a viable alternative. This should give you the info you need. It's an easy wire run.
http://www.*******club.com/tech/12v.html
I wired all my switches to 12v switched, which keeps me from leaving something on when it shouldn't be left on.