Peel the potatoes and slice them into 1/4-inch slices. Put them in a medium to large pot, and pour in enough water to cover them by about an inch. There should still be room above the water for it to bubble up. Place over medium heat, and bring to a boil. When boiling rapidly, reduce heat to low, and cook for approximately 20 minutes. You may test them by piercing a slice with a fork, and it should crumble. Do not overcook them, as they will be watery and mushy! Drain the cooked potatoes through a colander, and return them to their original pot. Add 1/4 tablespoon (or more) of salt, and 1/2 stick of butter or margarine. Use an electric mixer to whip this mixture until there are no lumps. Add 1/2 cup milk and beat completely. if you like them thinner, add more milk. Spoon the whipped potatoes carefully into a nice serving bowl, keeping all the air and fluffiness that you have beaten in. These are melt-in-your-mouth luscious! You will see them with my full cooked Country Dinner! Enjoy!!!