I don't often smoke a whole bird, but I do a lot of turkey breasts.
Most of the time I use soaked apple wood for smoke flavor, all of us, and the extended family, seem to prefer the apple over other wood smoke flavors. I put one good sized chunk directly on top of the coals and then put a filled metal smoke box next to it so the smoke lasts longer.
I only rub poultry seasoning over the dampened breast an hour or so before I put it on the smoker. Stuff the cavity with a good Vidalia onion.
For a hot smoker, I like to have a water pan beneath the grill, pour 1/2 bottle of cheap wine in with the water and a couple of bay leaves. Still can't remember why the bay leaves, something Mom did and Moms are never wrong!
For cold smoking, I keep adding apple wood chunks to the coals over the course, no water pan
I also like using briquets for smoking because they tend the burn at a better controlled rate and don't need as much tending to versus lump. Now, if I'm grilling a steak or burger, lump is the only way to go.
My bottom line is that it's really hard to mess up on smoking a turkey, they always come out better than one baked in an oven.