L.T.
My favorite place for younger skiiers is Heavenly Valley. A 3.5 year old isn't likely to be able to stay out for very long, and Heavenly was the only place that had a good indoor day care room for them to retreat to if the skiing became too much for them. The big downside with Heavenly is the cost though. They are pricy, but I will have to say that their lessons were fantastic, and my now 12 yo daughter loves skiing, can handle bad weather, all because of the prep work that went into her early ski lessons.
Also, my most important rule about skiing with a young child is that when they are done, you go in. Keeping a child out in weather they may not be happy with is the quickest way to get them to hate skiing.