Do NOT prick skin with a fork. (This allows the inside to caramelize.)
Place potatoes on baking sheet and put into hot oven.
Roast for 40 (smaller potatoes) to 60 minutes (larger). Turn potatoes once or twice during baking. You'll know potatoes are done when the outer skin pulls away from the potato. You can also carefully prick potato with a fork or knife, which will go through cleanly when potato is cooked.