Hi Mike and thanks for asking. The link that fv1989 will help with the instructor portion. Know that the instructors themselves get very very little of the ski school fees. Same as the drivers, they rely on tips to survive. Same as your wait staff in restaurants.
Shuttle driver get about a $1.00 a person more if they helped you with your bags. A family of 4 should give at least 5.00, same to the person at the hotel if they carry your bags.
Counter service like Starbucks Coffee usually gets the change or about 10%
Wait staff gets between 15 and 20% of the bill.
We don't usually tip the equipment rental folks unless they do something extra.
I find that a good tip and a good attitude often gets you more than good service.