Here's what I did - Particularly I want to point out my lower than some do internal temps - Post #4 onwards - STOP cooking when breast hits -- 160--, NOT more., turn off smoker (electric), or if not, pull, cover w foil and towels, let rest.
---- I have found dramatic difference in breast moistness when cooked to this temp compared to even just a few degree higher.----
I am very cautious about putting anything in the turkey cavity as it interfers with the heat distribution. Most articles you will find on smoking turkey recommend not to stuff them. Marctree is right on with his temps. If you take the turkey off the smoker at 158-160 and cover it with foil to rest for 30 - 35 minutes you will have a moist, fully-cooked bird. Higher temp than 163-4 and the turkey starts getting dried out as it will increase to about 170+IT as it rests.
NOTE: I brine my turkeys for 20 - 24 hours. I cook 16 - 20 pound birds and this amount of time seems to work fine. Then rinse completely and apply whatever rub, etc. you have planned (Jeff has a great one - his "Original" rub works for us). Also, check the bird occassionaly while it is cooking. If it is getting brown too quickly put some foil over it for an hour or so and slow that down. To make a perfect turkey takes a little more work than , say ribs; but you will wow your guests with the meat.
I do it what you might call plane jane I wash and rinse inside and out side well then I rub with a dry rub and put some rub inside. Then into the smoke at 225 and apple wood for the smoke cook to IT 165 no more than 170 let rest. Carve and serve. Note cook time depends on size of turkey can take as long as 14 hrs. at this temperature.