Potatoes come into two basic categories—bakers and boilers.
Bakers, relatively high in starch, cook up light and fluffy. They are ideal for baking, mashing, and French fries. Look for names such as Russet Burbank, Russet Arcadia, Norgold Russet, Goldrush, Norkotah, Long White (or White Rose or California Long White), and Idaho.
Boilers are relatively high in moisture and sugar but low in starch (starch holds the potato together when boiling or in stews and soups), making them ideal for soups, casseroles, potato salad, roasting, and barbecuing. When mashed, they tend to be thick and lumpy. Look for names such as Round White, Round Red, Yellow Potato, Red Potato, Salad Potato, La Soda, Red La Rouge, Red Pontiac, Red Nordland, Red Bliss, Yellow Finnish, Ruby Crescent, and Australian Crescent.
All Purpose potatoes are great for roasting, pan frying, and in soups, stews, and gratins. Moister than baking potatoes, they hold together in boiling water but can also be baked, mashed, and fried. Look for names such as Yukon Gold, Peruvian Blue, Superior, Kennebec, and Katahdin.
New Potatoes are immature small potatoes of any variety. Red potatoes are probably the type most often sold.