We can’t all be Martha freakin’ Stewart. If you’ve procrastinated, don’t panic. Just print out this list and get your butt in gear.

Wednesday Night

Get a head count. Call everyone and confirm. Don’t forget to ask about dietary quirks (so you’ll leave some stuffing out of the bird for the vegetarians, etc.). While you’re at it…
Get everyone to bring something. You can go two routes here. Either you make the bird and they bring everything else or you make the food and they bring drinks and dessert. Either way, there shouldn’t be any whining because the other stuff is easy and abundantly available this time of year.
Whatever your plan, tell everyone to bring a bottle of wine or a six-pack. If you’re just making a bird, then assign (nix the duplicates if you’re having a small crowd):

mashed potatoes
mashed potatoes
stuffing
rolls
rolls
veggies
dessert
dessert

Make your grocery list.
Clean out your fridge. You’ll need room for groceries tonight and beer tomorrow.
Clear off your counters, table, and buffet surfaces. Remove everything you won’t be using (toaster, blender, cookie jars, etc.)
Hit the store ASAP.
DO NOT BUY A FROZEN TURKEY. IT WILL NOT THAW IN TIME. It might seem like it will, but it just won’t. Even if you leave it out overnight and court salmonella, it’ll still be frozen in the morning. Don’t learn this the hard way. Buy a fresh one. And don’t forget:

a disposable aluminum roasting pan, plus any other disposable pans you might need (your grocery store will have one for every occasion
one of those roasting bags, if you really want to minimized cleanup
napkins or paper towels
ziplock bags or disposable containers to send home/pack up leftovers
butter
cheese and crackers, chips and dip, or some yummy prepared appetizer to keep everyone quiet if you’re running late
aspirin and Alka-Seltzer
coffee
desserts (2), unless you’ve assigned them. It’s way easier to buy them than make them, even if you start with a box.
flowers (you’ll look fancy and trick people into thinking you actually have your act together)
extra toilet paper
disposable cutlery, cups, and/or plates if you don’t have enough dishes/silverware
disposable or reusable serving ware or platters if you don’t have them
ice
a head of curly kale or romaine lettuce for garnishing, optional (cheap and easy way to spruce up crappy platters)

Count your chairs! If you don’t have enough seating, have guests bring extras.
Pick up the house. Stuff everything into back room closets. Avoid front room closets, as guests will open.
If you’re not exhausted yet, make a side dish or two.

Thanksgiving Day

Before anyone arrives:

Make your bed. That’s where the coats will go.
Put on some music, preferably an iPod mix or several CDs in a change so you don’t have to fret with records ending. This will relax you and make a nice atmosphere for your guests
Set the table or buffet before you start cooking. Put out glasses, napkins, silverware, etc. Make space for people to put their wine and any dishes they bring. You’ll thank yourself later.
PREHEAT THE OVEN. Everyone has a Thanksgiving story about forgetting to turn on the oven.
Put out the snack food. It will keep everyone from hovering around you whining “When do we eat?”
Start the turkey
If you’re concerned with your appearance, take a shower/dress/put on something nice before you get started with the sides. You’ll feel more confident if you’re not in pjs or a dirty undershirt when guests arrive. Wear an apron if you have one, or pin a dishcloth to your front.

Start the sides. Peel potatoes, prep vegetables, assemble casseroles.
Drink plenty of beer or wine as necessary.
Take out the turkey. While it’s resting, pop in the rolls, mash the potatoes, and take care of any last-minute stuff.