A good brine uses kosher salt and sugar in a 1-to-1 ratio, and usually no more than 1 cup of each. Feel free to add any other seasonings. Brines typically are made by heating the salt, sugar and seasonings with a bit of water until dissolved. This mixture then is diluted with additional cold water (volume will vary depending on the size of your bird) and ice. Be certain the brine is completely cooled before adding the turkey.
Turkeys should be brined for at least eight to 10 hours, but can go as long as 72 hours. A good rule of thumb is, the longer the brine, the weaker the brine. So for a 10-hour soak, use 1 cup each of salt and sugar. For a longer one, consider backing down to 3/4 cup each.
Always keep the bird refrigerated during brining. If the turkey is too big, an ice-filled cooler stored outside works, too.
Roasting temperatures vary widely by recipe. Some go at a slow and steady 325 degrees. Others crank the heat to 400 or 425 degrees for the first hour, then drop it down for the rest of the time.
However you roast, use an instant thermometer inserted at the innermost part of the thigh (without touching bone) to determine when your turkey is done. The meat needs to hit 165 degrees for safe eating, though some people say thigh meat tastes better at 170 degrees.
If the outside of the bird gets too dark before the center reaches the proper temperature, cover it with foil.
The following roasting time estimates are based on a stuffed turkey cooked at 325. Reduce cooking time by 20 to 40 minutes for turkeys that are not stuffed (estimate total roasting times at 15 minutes per pound for unstuffed birds). And remember, a crowded oven cooks more slowly, so plan ahead if your bird needs to share the space.