Haven't set one up myself, but I know a lot about 'em!
It's a rather broad question, really. But to answer your specific request, the surround speakers are often set in an array in order to broaden the sweet spot for the audience. As such, the speakers closest to the front on each side are typically at a lower level than the speakers at the furthest rear. This allows for a smoother transition from front to back in panned fx and whatnot.
When mixing on a dub stage, the size of the room is often the same as the final listening environment: the movie theater. So if you mix on a dub stage, you're almost guaranteed to have great translation. But if you mix at home in 5.1 or 7.1, you're typically in a smaller room, and thus don't need to worry about surround arrays. But this translates rather well too, assuming your room is tuned and balanced within itself. The arrays can have a smearing effect, or make it harder to localize a source sound in a specific surround speaker, but it's either that, or have only one person in the audience who can hear the mix as it was originally intended. Better to have the full audience at 90% translation than just one person at 100%, in all actuality. (Those percentages were just guesses, btw).
