Just as with any other turkey, a barbecued turkey needs to be cleaned out of all the innards and filled with stuffing. Cooking a turkey on a grill requires a large roasting pan that's made of heavy aluminum foil. The turkey should also be covered with aluminum foil and cooked for 20 minutes per pound at around 300 degrees, with the aluminum foil coming off for the final hour of cooking.
To barbecue a turkey, take out the cooking grate from your charcoal grill, and open the vents. Set the drip pan in the middle of the charcoal grate, and surround it with briquettes. Prepare the turkey like you would for oven baking, and cook it over the drip pan.
Take out the cooking grate, and open the grill vents. Center the drip pan on the charcoal grate, and put about 30 briquettes on each side of the drip pan. Burn the briquettes for about half an hour until they are covered in gray ash. Replace the cooking grate.
Take the neck off the turkey, and pull out the giblets. Drain all of the remaining juices out of the turkey, and use dry, clean paper towels to pat the turkey to remove moisture. Move the wings back to keep the neck skin from moving, and tuck the legs in. Spray or brush the whole turkey with olive or vegetable oil.
Set the turkey on the cooking grate with the breast facing up. Close the grill, but leave the vents ajar. Every hour or so, add eight more briquettes to each side of the drip pan. Test the turkey periodically with a meat thermometer, and cook until the internal temperature is 180 degrees Fahrenheit in the thigh (170 in the breast). Plan for about two or three hours for a turkey between 10 and 16 pounds. Remove the turkey when done, and allow it to stand for about 15 minutes before carving.