Preheat the oven to 350F. Line a baking pan with foil to make cleanup easier. Combine mustard, jam and sherry to make the glaze.
Score the ham in a diamond pattern, making the lines 3/4 inch apart. Brush ham with glaze and continue doing so every 15-20 minutes while cooking. If you have a large ham make sure you cover it with a foil tent to keep it from drying out.
The ham will be done when it reaches an internal cooking temperature of 160F.
Note: Partially cooked hams will need about 20 minutes per pound. Fully cooked hams will only need about 10 minutes per pound.