answer:I usually use a russet potato, the brown skinned baking type, but any potato would work. Just depends on the size for the baking time. A large russet takes about 10 minutes, maybe a minute or two more, you have to check by squeezing it. I scrub my potato, dry it with a paper towel, poke about 6 holes in it for ventilation, rub in olive oil, or butter, and put in a ceramic, microwave safe, bowl or on a plate. Cover it with a damp paper towel and bake. For a smaller red or gold potato I would check it after about 5 minutes. If you cook too long the ends will become rock hard.