We worked there April to Nov 2011. It is a magical place!
Ditto to all info above. We bought a 'booster' and did get some signal for ph and Internet. It wasn't as fast as if you were at home, but we got it. We were in Canyon Village at 7800' elevation.
As far as working there, it depends what job you have and WHO you are working for...we worked for Delaware North in a store. Get used to things being 'oh that's the way we've always done it..' Don't look to improve anything.
And depending on your schedule, take advantage of the time to get out and explore. Your time will FLY by!!