I just rub my chuckies with some Worcestershire sauce and sprinkle on some Montreal Steak Seasoning and place it into the smoker. Depending on whether I'm going to slice it or pull it determines to what internal temp I take it to.
If you want to save the drippings to make some gravy, put you roast in an disposable foil pan.
Now I have used alot of differant rubs and spice combos on chuckies so it's really up to you. Do you like hot and spicey or are you a mellow kind of eater. there are as many rubs out there as there are smokers too. Now I personally like alittle more heat and I like the old bay rubs, or there's a good one by Gates that is good on a chuckie. Then some just use salt, pepper and some garlic and let the meat speak for itself. Now thats always a good one for me too. But I would rub it the night before and then set your smoker at about 230-245° or so and then take it to 165° spitrizing every hour after the first hour and then foil it at 165 and then take it to about 205° then more foil and into a dry cooler for atlaest and hour. Then pull it and enjoy