How to Choose Potatoes and Sweet Potatoes

With such a bewildering variety of potatoes and sweet potatoes around today, how do you know what to pick?

Instructions

Make sure any potato or sweet potato feels heavy.
Avoid any potato with decayed areas (usually at the ends), blemishes or sunken spots.
Choose potatoes of comparable size for uniform cooking.
Pick russet potatoes (the normal brown kind) for baking or mashing. Russet potatoes turn mealy when cooked and start to fall apart when cut.
Select yellow, white or red potatoes for boiling, steaming, roasting or gratins. These potatoes have a firmer texture and won't fall apart when cut. Yellow and red potatoes can also be mashed, but they won't be as fluffy as russets.
Choose sweet potatoes with orange, moist flesh (often mislabeled as "yams" in supermarkets). These potatoes have a sweeter taste than those with yellow, dry flesh.