Right 1st you want to get hold of a turkey, frozen will need to be defrosted completely, or fresh from your butcher or if you're that way inclined go and kill your own bird, just remember that it needs to be at room temperature and the feathers must be removed, before it goes onto the smoker... this will ensure that the smoke penetrates.
Insert pesto/ rub or your own "secret" mixture (we all have one) underneath the skin.
Once you have about 3 table spoons of the mixture under the skin, use your hands to gently massage the bird, in order to get the mixture spread evenly..... believe me, there'll be quite a few blobs off the stuff lying around your work area (it's a messy process), and if your work area was hygiene friendly to start with, use these wayward blobs to rub the outside of the turkey... this'll help whatever herbs and spices you use to stick to it.
You want to maintain a cooking temperature of between 200 - 250 Deg F for about 5 hours. Throw some wood chips/ chunks on to the coals every 30 minutes or so, depending on how much smoky flavour you require. I usually check the internal temperature of the turkey at about 4 hours into the cook, by inserting a food probe thermometer into either the thickest part of the breast or thigh. The bird is done when the internal temperature reaches 165 Deg F. A point to note is that once removed time must be allowed for the meat to rest and that during this time the meat will continue to cook as the juices re-distribute themselves.