Don't know where you are BOP, but will assume US.
As you say, turkeys come with instructions on the package. That's the big thing out of the way.
1)If you are into stuffing (dressing), Mrs Cubbison's is your friend.Instructions are on the box. And it is not required to stuff the bird with it. I make it in a casserole dish. And I prefer the one that says 'seasoned bread crumbs' on the box.
2)If you or your guests have an aversion to canned cranberry sauce, try this:
1# fresh cranberries
2 navel oranges
sugar to taste
Dump the cranberries in a food processor. Chunk the oranges, including the rinds, and throw them in. Process them until chopped in tiny bits, but not pureed. Add sugar. Refrigerate and you're good to go. This is actually better if you make it a day or two in advance
3)I will assume you know how to make mashed potatoes.
4)Gravy, must have gravy. Take the neck and giblets (liver, heart, gizzard) from the turkey and throw them in a large pot with several ribs of celery, a large onion cut in quarters, about two quarts of water, and about a tablespoon of poultry seasoning. Simmer for a couple of hours while the turkey is roasting. Fish out the neck, giblets, celery and onion and chop them up (about the size of a pea). Reserve about a quart or so of the broth to the side so it will cool. Throw the chopped stuff back in the pot. After the turkey is done and removed from the roasting pan, pour the pan drippings in with broth/giblets. Add about 1 teaspoon of Kitchen Bouquet (this is a browning/flavoring liquid). This is usually found on the aisle with the salad dressings etc. Add flour a couple of tablespoons at a time to the reserved broth, whisking briskly, side to side, not round and round. This is called a slurry, and should be a little thickish, but not so that the whisk stands up on the bowl. Then add the slurry a little at a time into the simmering broth with the giblets etc, whisking as you pour it in. This slurry is what will thicken your gravy so that is gravy and not au jus. If the color seems a little pale (like flour paste from grade school), add a little more KB.
5)Pies. Marie Callendar frozen at the grocery store is your friend. So is Village Inn for non frozen.
For any other sides, vegetables, rolls, etc etc: Seriously, ask your guests to bring something. I have been doing Thanksgiving for my relatives since 1973. Fewest people, 5. Most people, 27. Each family group always brings something. And if you are having a crowd, do yourself a favor and use disposable plates. I use Solo brand plastic type ones. The plastic means they don't get soggy from gravy. I also use those rattan paper plate holders for stability and so the bottom isn't hot in your hands. We do use real silverware, and I count it before the garbage goes out
This is probably far more info than you wanted, but....
Good luck, and feel free to ask any other questions.
MM