Ways to fuck up include: poisoning your guests with the turkey, forgetting you put the turkey in the oven because you got drunk and fell asleep in the bathtub, and, of course, failing to do those important turkey things that are really obvious to everyone but you.
First of all, thaw your turkey in the refrigerator, allowing at least a few hours per pound. When he's good and defrosted, rinse and gently pat him dry.
Next, remove the neck and giblets (crucial, or everyone will totally know you're a turkey virgin).
For an extra tender turkey, soak him in brine solution or give him a little rub down with olive oil or butter.
Stuff him immediately before cooking, unless you want to give your guests salmonella--in which case, stuff it the day before and leave it out overnight. Use about 3/4 cups of warm stuffing per pound of turkey, and don't overstuff or your turkey will explode. Place stuffing in both the neck and body cavities, and pin the neck flap closed with toothpicks or metal skewers.
For the full Martha Stewart experience, truss the turkey ("truss" means "tie up real purty") by tying its legs together with string or cooking twine, and tucking the wingtips under the body. Cook him breast side up--check a time-table to find your cooking time (based on pounds), but use a meat thermometer to make sure you don't overcook.