For a large party, you'll need a big bird -- say, 15 to 20 pounds; figure 1 1/2 pounds for each person. Smaller birds -- 12 pounds or less -- have a smaller meat-to-bone ratio, so allow 2 pounds per person. Remember that the larger the bird, the more likely you are to have leftovers for the next few days.
Leftovers can serve as the main ingredients for dishes you might not otherwise make. Sliced turkey can become the main ingredient in an open-faced sandwich, a turkey-and-green-chile burrito, or a turkey-salad sandwich. Even the turkey bones can have a second life: Use them as the basis of a delicious turkey stock, which can be frozen for up to four months and used in any recipe calling for chicken stock.