The International Dark Sky Association has a list of places to consider.

If you're looking for something closer to home darkskymap has a google maps overlay (search for where you are, probably obvious how the overlay works — darker is better).

That said, even in dark places you have to get far from ‘civilization’ to avoid skyglow. For instance our place in Maine is in a relatively dark area (Bortle 2 for astronomers out there) and I still get a bit of light over the horizon.