A nutrition specialist with the University of Missouri Extension Service says the most important thing to remember when preparing the Thanksgiving meal is to properly roast the turkey. Susan Mills-Gray with the Cass County Extension Office in Harrisonville says a 10 to 15 pound turkey needs to be in the oven between three and four hours at at least 325 degrees. She recommends testing the temperature with a meat thermometer. Mills-Gray also cautions against letting the turkey near other food to guard against cross-contamination.