This sport is a Canadian invention, having been jump-started by Bombardier's invention of the Ski-Doo snowmobile. It became a major recreational sport in the mid-sixties, and has become a great family winter sport. Today's snowmobiles are quieter, more stable, and more reliable than the early snowmobiles, and some models are downright luxurious, with foot and snack warmers aboard.
To drive a snowmobile, remember that you throttle (accelerate) with your right hand and brake with your left. You straddle the seat cushions, and rest your feet on the running boards, letting your legs absorb the bounces on the bumps. Today's snowmobiles can go as fast as 100 km/h, though you do not want to go at speeds beyond 50 km/h if you wish to see the natural terrain around you.
For safety, when snowmobiling, stick to marked/tracked trails, carry emergency food & fuel, and if in the backcountry, carry emergency transceivers.
To go snowmobiling you need a snowmobile, and a truck or trailer to carry it. You do not need a licence to drive a snowmobile, but the vehicle must be registered with the provincial Motor Vehicle Branch. Snowmobiles can cost from $4000 to $15000, with trailers starting at $400. Fortunately in good snowmobiling areas, you can rent them by the hour or by the day. You should also wear warm winter clothing, like a one or two-piece snowmobile (or ski) suit, goggles and helmet.
There are snowmobile tour operators in the Alberta Rockies at Banff, Canmore, Jasper, Hinton and in Kananaskis Country, and in the BC Rockies in Fairmont, Golden, Panorama, and Cranbrook. Snowmobiling is extremely regulated (effectively prohibited) inside the national parks, to minimize disturbing the wildlife. Kananaskis Country offers over 200 km of groomed trails in the Cataract Creek and Etherington snowmobile areas. There is excellent snowmobiling at Maclean Creek, west of Bragg Creek, and anywhere in the Columbia River Valley in BC. The Blairmore-Crowsnest Pass area (along highway 3) offers 1,200 miles of groomed trails ,some of which cross the Continental Divide.