Hi Danny,
I am glad to hear that you like the books. Believe me, it's a lot of fun to put them together.
I do recommend water in the pan. After all, it is a water smoker, and the water serves at least a couple important purposes. It adds a little bit of humidity to the smoking environment, which is really good, especially when you are smoking meats for long, long time. The extra humidity helps to keep the meat moist. The water also helps to keep the temperature nice and low by absorbing some of the heat in the smoker and releasing it slowly. Without the water, I find that the temperature tends to climb too high.
Thanks for the question.
Jamie