A baked ham slathered with a sweet-tart glaze is the holiday cook's greatest ally. There's no real cooking involved; you simply heat it through. But to the uninitiated, buying a ham can be a bit intimidating, so it helps to know what you're looking for.
A whole ham is the entire hind leg of a hog; it can weigh upwards of 15 pounds. Far more common are half hams. The one pictured here is a shank-end ham -- from the part of the leg closest to the trotter -- and that's what you want. The shank has less connective tissue and fat than the butt end, cooks more evenly, makes for a more striking presentation, and is easier to carve.
Hams are cured by various methods, and here, too, you should know the lingo. A "country" ham is dry and intensely salty. It has its place (in biscuits), but a more typical offering is the so-called city-cured ham, which is tender and succulent. It may be labeled "partially cooked," but the preparation is the same regardless.
First, use the tip of a sharp paring knife to score the ham with quarter-inch-deep parallel lines, one inch apart. Score the skin in the opposite direction to create a diamond pattern. Place ham on a rimmed baking sheet lined with foil, then parchment; tent with foil, and bake in a 300-degree oven until heated through, about 15 minutes per pound. Remove the foil, and brush the ham all over with a glaze. Bake it 15 minutes more, and then brush with more glaze and any juices on the baking sheet. Finally, bake it until the skin is burnished, another 10 to 12 minutes. Transfer it to a carving board to rest at least 15 minutes before slicing. After guests have eaten their fill (including sandwiches the next day), you'll be left with a magnificent soup bone.