Ribs are one of the few meats that are Never cooked to Temp! It just don't matter, Ribs are done when they are Tender from having cooked a sufficient amount of time to break down the HUGE amount of tough Connective tissue that binds the muscle between and to the Bones. Here is the whole deal in a nut shell and a good starting point...
A full rack of Spare Ribs will take about 6 hours at 225*F...The 3-2-1 smoked rib recipe is a good way to smoke ribs and tends to turn out near perfect ribs every time whether you are using the meatier Full rack spare rib or the Saint Louis cut. Baby Back ribs use a 2-2-1 method. The ribs are smoked at 225 - 250 degrees for best results...
The 3 stands for the 3 hours that you initially smoke the ribs with nothing but your favorite rub on them and some smoke with your favorite hardwood such as hickory, mesquite, apple, pecan, etc. After the 3 hours you remove the ribs and quickly double wrap them in heavy duty foil.. just before you seal them up add some Apple Juice or Foiling Juice and close the foil leaving some room around the ribs for the steam to be able to flow around the meat and Flavor/Tenderize it. I like meat side down for this step.
The ribs cook in the smoker wrapped for 2 hours undisturbed. There is no need for Smoke at this point... After 2 hours remove the ribs from the smoker, unwrap and place back into the smoker for the final 1 hour, with smoke if you wish.This firms them up, creates a nice Bark and finishes the cooking process. You can add a glaze or sauce at this point if you like. The meat will be pretty close to fall off the bone and be extremely juicy, tender and flavorful. You might enjoy this recipe...JJ
http://www.smokingmeatforums.com/t/110881/foiling-juice-chef-jimmyj
Here is some greater detail and nice pics of what you are looking for...
http://www.smokingmeatforums.com/a/smoking-ribs