A little salt, ground pepper, and a pinch of cayenne will do great as a rub. If you have time, put the rub on (sparingly with the salt), and let it "dry brine" in the fridge for a couple hours. Then smoke at 225-250 for 4-5 hours. I don't foil mine. If you want to put a little sauce on yours, brush the sauce on at the 4hr mark and let it cook in.
Alternatively, if you get your hands on some Obie-que "Smooth Move" rub, that works great on Beef Ribs.
The thought of some beef ribs is making me hungry right now!