Hey y'all, I just put my new electric smoker in service and I have a few questions: 1. My instructions don't mention anything about using water. Is water necessary or not, and if so how much should I use? 2. Does the smoker need to be preheated prior to placing the meat in it or should I just put the meat in and turn it on? 3. Does anyone have any suggestions for a dry rub for a Boston butt? Thanks in advance for any help.