Verbinet provides what i believe is the best list of official ski schools in Verbier. Check these out but beware, your company may well have some kind of discount with a certain school.
I visited the beautiful town of Verbier, Switzerland this winter for two and a half months working for a company who I will keep in the dark as i do not wish to advertise them in any shape or form hence the reason i did not finish the season. boo hoo!!! However I did have the time of my life and im here to share the town with you and perhaps give you some tips on who to travel with and where to visit from a seasonnaires point of view.