Always use remote probe thermometer. Cook until the breast reads 165°F or thigh reads 180°F.
Turkey is usually done if the internal temperature of the turkey rises to within about 5 to 10 degrees of desired finish temperature and temp does not increase over the course of the next 45 minutes then remove and check.
Brining over night in a salt water solution will provide a juicier turkey. But if you have never brined before go easy on the salt.
Cooking whole or half turkeys breast side down will allow the juice and fat to drip through the breast for a juicier turkey.