My mother always baked a ham at Christmas and Easter time. She taught me how to make this. It so dang easy and the ham comes out absolutely delicious. You'll have a hard time keeping everyone away before its dinnertime.
Place ham in sturdy baking pan. Pour root beer over ham. Cover with foil and bake in a 350 degree oven for three hours. Basting ham occasionally with drippings, about every half hour. If necessary you may want to put a baking sheet under the roasting pan so as not to spill inside of your oven.
After two hours, remove foil. Place brown sugar in a bowl and add drippings from the pan to create a loose paste. You want this to stick to the ham.
After a half hour, take ham out in order to place pineapple rings on ham with toothpicks. Then place a cherry inside of each pineapple. Then add more cherries if you want all over cause they are yummy!
Bake ham uncovered for another half hour. Remove from pan for slicing, let it rest first.