Go buy a WSM. Assemble. (I'm not saying WSM is the only and best cooker out there, but for the $$$, for the ease of cooking a butt, and for those long cooks, it's not a bad place to start.)
Buy butt and buy whatever rub you think has a cool label.
Fill bottom ring with kingsford blue. Light with minion method.
Let temp get to 260.
Put hot water in water pan.
Put butt on.
Cook for 10 hrs or basically until charcoal dies out.
Get favorite red sauce and add a little water and apple cider vinegar.
Wrap in foil and put in cooler for 1.5 hrs.
Pull apart with fork and pour sauce over.
Drink beer and thank me/brethren later.
18.5 WSM/22.5 OTG/Modified New B. Offset/Brinkman Gasser