Ron,
Luckily, it's pretty hard to ruin anything on the WSM. If you take the skin off, the meat will acquire a sort of "case hardened" texture at the surface, but if it's not over or under cooked, will be fine. Many people like to keep the skin on there so it bastes the meat as it cooks, helping to keep it moist. The smoke flavor seems to find its way in there either way. A compromise is to loosen the skin by running your fingers between the skin and the bird. Then, if you want, you can put herbs, spices, garlic, butter, etc. under the skin next to the meat while it cooks. That is how I do turkey breasts: pull the skin off, put butter and spices on the breast, then set the skin back in place before cooking. Chickens are tricky because they are not of uniform thickness all over, and they have two distinctly different types of meat (white and dark) which are best at two widely different temperatures. Best bet: grab a few chickens and experiment. See what works best for your tastes.
George