How do you interact with an amish person?

Serious question, an amish guy is coming to work at the sawmill I work at, evidently out of desperation, his sister needs serious medical treatments and he's trying to come up with the money--I sympathize with his situation, and don't want to offend him or make his life any less pleasant right now, and know virtually nothing about these people aside from the movie Kingpin and that one Weird Al song