Cooking Turkey for Beginners - An Easy Step-by-Step Turkey Recipe

Roast at 325 degrees F., for approximately 15-20 minutes per pound. This is just an estimate - be sure to use a meat thermometer to get a perfect doneness.

Remove the turkey when it reads 165 degrees F. in the thickest part of the thigh meat. Here is an approximate turkey cooking time guide for roasting at 325 degrees F. from the USDA:
8 to 12 lbs: 2 3/4 to 3 hrs
12 to 14 lbs: 3 to 3 3/4 hrs
14 to 18 lbs: 3 3/4 to 4 1/4 hrs
18 to 20 lbs: 4 1/4 to 4 1/2 hrs
20 to 24 lbs: 4 1/2 to 5 hrs

While roasting, the liquid can be used to baste the turkey (there is a debate whether basting does anything, but it's part of the tradition).