Northstar (at Tahoe) Resort
If you are a skier, then you have probably done the research on the Tahoe resorts to know what areas are of interest to you.
But if you have never gone skiing/snowboarding, or if you simply want to go sledding, then I recommend Northstar. It is just outside of Truckee, so it is the easiest to get to. It is also predominately an intermediate skill level mountain, so you can find a greater number of easy slopes that will not intimidate a beginner.
In the summer, the hills are also open to a range of mountain biking and hiking.
Other local resorts like Squaw, Alpine, Sugar Bowl, etc. cater more to advanced and expert skiers. All equipment is available for rent, but to save some money, bring it if you have it, or try renting from a more economical shop in town.