The Ski Area consists of two very different areas: Dollar Mountain and Bald Mountain. The Bald Mountain in turn has two base lodges: the River Run and the Warm Springs. Movement between these three is relatively easy, as the shuttles are run on a regular basis. The shuttles are equipped with the ski racks, plan about half an hour for a trip. The area is totally uncrowded outside of the Christmas-New Year season, there is no waiting for any of the lifts, period.
Dollar Mountain has (very few) easy slopes and a terrain park. The slopes are intended for the beginners, they are mostly green or have a light shade of blue. The skiing area is tiny, runs are pretty short; I would only use Dollar for warming up on a first day, testing new skis, etc.
The Bald Mountain is a beast that a beginner shall avoid, and a low-intermediate skier handle carefully. It is essentially a black mountain disguised for commercial reasons as an easier one. The only true green run here is the bottom part at the River Run lodge. All other labels on the runs down the Bald Mountain are deceiving and shall be increased by one level (green to blue, blue to light black). In particular, there is no easy home run from the top of the mountain to the Warm Spring base. What is labeled as a greenish path on the map is actually a solid blue slope that under some snow conditions can be quite black. The run from the top towards the River Run is easier, but its green label is misplaced, too: it is a truly blue slope in some parts. You've been warned: save some strength in your legs for this last run. The advantages of the arrangement are clear: pretty much everyone on the slopes knows what she is doing, the lifts practically never slow down to accommodate beginners that are learning to load/unload.
Regulations in the Sun Valley area prohibit residential construction on the slopes, so there are effectively no true "ski in-ski-out" accommodations. The closest place resembling it is the area around the Warm Springs Lodge that requires just few tens of yards of walking to the lifts. In the River Run and Dollar areas you will have to use a bus (car alone is not sufficient, you will still need a shuttle from/to the parking lot).
The skiing season is guaranteed all the way from Thanksgiving to Easter due to the vast array of snow-making machinery. The air is very dry, so the slopes feel powdery most of the time, but in the times with low levels of natural snow, there is a very hard base of artificial snow underneath. The snowboarders might pull the snow into bunches resembling small moguls with exposed patches of hard surface in between. I am not the best of skiers, and I was forced to change my skis for a much more aggressive pair to avoid unintentional sliding down on these patches. Not all slopes are groomed; the "groomed" description of the run on the web site does not mean that the entire slope is groomed. That said, a powder day here is pure delight.
Food is available in the lodges during the day time, there are restaurants in the Sun Valley proper and Ketchum (the town at the base of Bald). There is a major grocery store in Ketchum.
Closest comparison I know is Sun Peaks in British Columbia. It is equally hard to reach (minor airport with a half an hour to an hour ride to the resort), equally uncrowded and geared for skiers and families with kids. Sun Peaks skiing area is way larger and ski-in/ski-out accommodations are possible, but Sun Valley appears to have more of the difficult terrain. read more