To prepare potatoes, rinse them under cold water and scrub them well. Then, peel or leave the skin on depending on your recipe. To cook potatoes, they can be boiled, baked, fried, or roasted. Boil potatoes for 20-25 minutes until tender, or bake them in the oven for an hour at 400 degrees fahrenheit. For crispy fries or hash browns, fry them in oil, or roasted them in the oven for 30-45 minutes.