Question on beer-can turkey

I want to do a 23-lb turkey the beer-can style. I read in an earlier string that you should do 325 degrees for roughly 15 minutes per pound. Is that right? Also, what else do you put in the beer can--garlic, olive oil, other stuff or just beer? And do you put foil around the bird to keep it from burning the skin?

Finally--sorry for all the questions--do you still cool the breast with ice prior to cooking?

Thanks!