It seems simple enough. You go to the store, pick up a turkey and you're done. Well if you care about how your turkey is going to turn out then you should know a few things. It is important to read the labels on your turkey or better yet to talk to your butcher. Also, remember if you plan on ordering a special turkey (free range, all natural, etc.) you should do that early and make sure you can pick it up in time to prepare it the way you want.
The general rule of portion size says that you should plan on 1 1/3 pounds of turkey per person. If you are feeding 10 people this Thanksgiving you should plan on a 13-pound turkey. Of course, this isn't going to leave you leftovers for sandwiches on Saturday. If you want a good amount of leftovers to plan on 2 pounds per person, or in this case a 20-pound turkey.
Tom vs Hen
In days past hens gave you more white meat to dark meat. With recent selective breeding Hens (female) and Toms (males) have about the same ratio of white to dark meat (mostly white meat). The difference these days is the size. Hens typically weigh in between 8 to 16 pounds and Toms are generally 10 to 32 pounds. What this means is that the weight will determine whether you buy a Hen or a Tom
Fresh vs Frozen
Thanks for heavy lobbying by the Tyson Corporation the definition of "fresh" when it applies to poultry means it has never been cooled to lower than 26 degree F.
Now I promise you, if you pick up a turkey at 26 degrees F it is hard as a rock so the term "fresh" doesn't really mean anything when buying a turkey at your local store. It just means that it hasn't been hard frozen. Truth is, flash frozen turkeys (frozen fast to below 0 degrees F) can be fresher tasting that many "fresh" turkeys that have been sitting around for a few months.
To further complicate matters the USDA definition of frozen means that the turkey has been brought to a temperature no lower than 0 degrees F. Turkeys stored at a temperature of 5 degrees F can actually be labeled "not previously frozen", though they can not be labeled as fresh. These turkeys are considered "hard-chilled" or "deep-chilled". Personally, I call temperatures between 0 and 26 degrees F something other than chilly.
Natural, Kosher, or Self-Basting
By law, a turkey labeled natural have minimal processing and do not contain any additives. Kosher turkeys are grain feed and allowed to roam free. They are treated with a brine solution before packaging. These are good birds to cook because they are all natural and have a good flavor. Self-basting turkeys are injected with a solution to "enhance" the flavor. This solution is high in salt and while it does affect the flavor the real marketing advantage is that it increases the selling weight by as much as 15%, making it look like you get a bigger bird. I recommend getting a natural turkey. Remember: DO NOT brine a Kosher or Self-Basting turkey. It will be too salty.
One quick not about hormones and antibiotics. The rule with poultry is that it can not be given hormones of any type.
As for antibiotics, they can only be used for the health of the turkey if a withdrawal period is given to allow the antibiotics to leave the birds system. So if you find a someone marketing hormone free turkeys point and laugh at them, then walk away.
It is important that you read the complete label of the turkey you buy. Because marketers have found many ways to put advertisements on the packaging of turkeys it is important that you ready the label that they can't alter or lie on, the list of ingredients. Here's where you will find out for sure.