I smoked a duck for the Christmas meal this year rather than smoking a turkey (I roasted the turkey).
The process I used for the duck was relatively simple and straight-forward:
1/2 onion in the cavity
2 cloves garlic in cavity
Liberally salt and pepper skin
5lbs of lump charcoal
Several chunks of store-bought hickory chunks
1.5 cups whisky in water
Thyme & marjoram in water
After two hours it started raining, which dropped the temperature of the smoker. After four hours of smoking, at which time the duck should have been close, if not done, I brought it inside and put it in the convection oven at 350° for another hour to finish it.
Here are my tips for a successful smoked bird:
Let the turkey come to room temp before putting it in the smoker. This helps ensure the meat cooks evenly.
Pat the turkey dry with paper towels before prepping it. Water is a heat-sink and will slow the cooking process and also possibly lead to uneven cooking.
Liberally apply salt and pepper to the entire outside of the bird as well as into the cavity. You don't need to stuff butter under the skin or inject the meat with anything. S&P is all you need!
Truss the bird to help achieve a uniform shape and thickness, which helps with even, consistent heating.
Season the water to impart subtle flavors to the skin and meat
Use freshly-cut, green wood for smoking. It imparts much better flavors than store-bought chips
Don't use Matchlight charcoal, as it imparts a "lighter fluid" flavor
Cover the meat with foil and let it rest after you've removed it from the smoker.
Keep good notes on what you do each year so you know what worked and what didn't.