I am going to smoke this weekend for the very first time. I just purchased the Smoke Hollow 4 in1 grill and plan on using the smoker to smoke a Boston Butt. I should have the mods recommended done by this weekend and I just purchased the Maverick ET732 thermometer. While researching smoking I've seen people using a tin of water. What is the purpose and where should it be placed? Also, will the thermometer have the instructions showing how to properly place it in the grill so that I am using it properly? I will probably smoking a Boston Butt around 6 lbs. I'm figuring about 7 or 8 hours of smoking. Does that sound right? Probably real basic questions, but again, I've never cooked this way before. Thanks in advance.