Hi Brett...I started out with the 3-2-1 method of foiling ribs, etc, but I have moved away from that approach. It was a lot of trouble fumbling with the foil without really better results. So, here's what I do: rub the ribs down and let them sit in the fridge wrapped in plastic for a few hours, preferably overnight if you can. Put them in the smoker, bone side down on the racks, set for 235F with 3-4oz of wood (I like hickory), and let it go for at least 4.5 hours --- no peeky!
After 4.5 hours, I take mine out and apply some BBQ sauce, then back into the smoker for one last hour. This is an optional step, but I like to have the sauce applied before the ribs are done. If you don't want to sauce, then leave the ribs in the smoker, but you might want to start peeking at the 4.5 hour mark just to see if the meat is pulling back from the bone.
My ribs almost always come off at 5.5 hours, but again, you will want to check yours for doneness, starting anytime after 4.5 hours.
Good luck...I know you will have a smashing success! Enjoy.