Ham is forgiving. Ham wants to be juicy. Ham loves a good glaze.
The only sin is overcooking. A dry ham is a sad ham. A dry ham makes your guests politely chew for ten minutes.
So remember: 140°F for cooked, 145°F for raw, rest before slicing, and use a real thermometer. Now go forth, roast that glorious pork leg, and make your kitchen smell like a holiday story. You got this.