Hey Bear - congrats on the new cooker. We probably need a little more info then it's an 80 gallon smoker - are we talking an offset?
When I cook ribs, butts, and brisket I like to shoot for 230ish degrees - nice and low. I start figuring 1.5 hours/ pound then add 2-3 hours. The one thing you don't want to do is rush your cook.
I like to do chickens hotter - 275 - 325 to crisp the skin - nothing like rubbery chicken skin to ruin your appetite. One thing you can do is (if you hare running an off-set) is to put your butt on early, the chickens shouldn't take more then 2-3 hours tops - when you do put the chickens on put them on closer to the fire box.
Do you need water? I sometimes put a pan of water close to my fire box, but it's not a necessity.
Good luck and let us know how you make out!