Northern Ontario Travel has posted a great beginners guide to Snowmobiling Touring. They have made a list of important things to consider before making your first trip. Their article goes over important steps such as "Where to Start", "Baby Steps" and "Study a Map".
They also make the great suggestion of planning for the worst case:
"As much fun as snowmobiling is, the nature of the activity places you in a less than hospitable environment. Sub-zero temperatures and a long way from help, any complications on the trail and your survival is on you. First aid kit, starting a fire, shelter, repairs, think about it, plan for it, hopefully you will never need to apply it."
To read the entire Northern Ontario Travel guide click here.