Here is a planning checklist to get you started:

1. Consider the number of guests you're inviting. Do you need extra chairs or place settings? Will your casserole dishes hold enough to feed the number of people, or will you need to make two of some dishes in order to accommodate a large group?
2. Decide who will help you by bringing portions of the meal or tablecloths, extra chairs, etc. Will you prepare the entire meal in your home? Will guests be in charge of bringing wine or cider for the meal? Do you need someone to bring extra serving utensils so you won't run out?
3. How will you cook the turkey? Whether you plan to brine, smoke, fry, baste or barbecue, there is plenty to consider with the turkey. Make sure you have a roaster large enough for the turkey you're going to be making and a working thermometer. Do you need any other specialty equipment like a fryer and oil, an oven bag or a serving dish? Now is also a good time to make sure your carving knives are sharpened.
4. Choose your bird size. A good rule of thumb is to assume 1.5 pounds per adult. This should hopefully give you some extra for delicious leftover meals. Turkey wild rice soup is one of my favorite leftover dishes.
5. Pick your dishes. Will you be trying any new recipes? Now is a good time to try them out so you don't have any flops on Thanksgiving. Will you be serving an alternate meat like a ham or main course? Make sure you have the oven space or make plans to have someone bring in already cooked items that can just be reheated that won't fit.
6. As we get closer to Turkey Day, clean out the refrigerator to make room for all the Thanksgiving fare that is going to occupy it. Purchase canned goods and items that won't wilt or rot. Wait until a day or two before to pick up any produce you're going to use.
7. Make a list of how long and at what temperatures dishes bake at. Decide if you can make any ahead and simply reheat when it's time to eat. Some dishes that can be done ahead are sweet potato casserole (just wait and add the topping while you're reheating), cranberry sauce (which can also be served cold), and pies. For pies, just toss in the freezer and then bake slightly to give them a nice, crisp crust so they taste like you slaved all day over them.
8. Get ready for the big day. Clean the house a few days in advance so you're only touching up and doing surface cleaning right before guests arrive. Last minute food preparations should include salads, turkey, setting the table and following the cooking schedule you made earlier.
9. Enjoy your family together time!