Keystone ski school has a good reputation; I have not taken lessons there, but Bob Barnes (often found on this forum) used to teach there- maybe he can give you some advice on instructors to ask for.
Summit County finally got hit with some substantial snow this weekend, so the base depths are finally over the top of the grass. Actually, when I skied Keystone last week, despite the scant coverage, the snow was surprisingly good, especially on the sides of the trails, considering what they had to work with. I am assuming it is considerably better now- it certainly was at Breck today.
I agree that the rental option is probably the most economical bet from DIA, but I would give the shuttle services a call- they may have a family plan (I know that Supershuttle from DIA into Denver does, with either substantial discounts or free for kids.) Worth an inquiry on an 800 number.
The only thing you will need a car for is if you want to go into Dillon, Silverthorne, Frisco, or Breck for shopping or entertainment. Everything else should be accessible by foot. I believe that the Summit Stage (free bus transportation) stops in most locations at Keystone, too. The food shopping at Keystone is fairly limited, but there are the usual overproced grocery stores. There's a huge supermarket in Silverthorne that is right on the way to Keystone (a few miles away). When I last used the shuttle service from the SLC airport to Snowbird, they would make a supermarket stop on the way for fairly reasonable extra fee. Maybe they will do this here as well.
[ January 04, 2004, 10:24 PM: Message edited by: dp ]