How would you go about being a groomer-

e-mail a resort and they'll probably tell you the information perhaps?

I'd say a lot of people who get into it are probably already working for the department, like ground crew and stuff. Your best bet would be to go see if you can get a ride in the snow cat with a current groomer and talk to them about the job, I doubt they would be pissy with you just for being interested. I don't know about Oz but I've heard places like Mt. Washington give free cat rides to customers who are interested in that sort of thing.