To preserve the moisture in the ham place the meat cut side down on the roasting pan and cover the ham with a foil tent. Remove foil for the last 15-20 minutes of cooking. To burnish the glaze, turn your oven to broil for 5 minutes. Watch the ham carefully, these glazes are high in sugar can burn easily.
Partially cooked hams need to be baked about 20 minutes per pound, until the internal temperature reaches 160°F. Fully cooked hams need about 10 minutes per pound baking time, and an internal temp of 140° F is desired.
You can buy bone-in or boneless hams. Bone-in hams tend to be more flavorful, but they are more difficult to carve. If you serve a bone-in ham, figure on 1/2 to 3/4 of a pound per person. For boneless hams, 1/4 to 1/2 pound per person is more appropriate. Leftovers are great, don't be afraid to buy a little more.
Spiral sliced hams are fairly recent (at least as far as ham goes). These are fully cooked hams, sliced using a special machine so the meat literally falls apart into thin slices. These hams usually have a glaze baked onto them so all you need to do is heat the ham according to directions that come with the ham.
Leftover ham should be stored in the refrigerator for up to 3 days. For longer storage, you can freeze the ham and store it up to 2 months.