Costco or grocery stores will carry prepped (uncooked) ribs. These are super easy to cook with great results.
What to buy
Costco has two-packs of marinated slabs for about $3/lb. Be sure to call your neighbors to see if they want some, because 2 slabs is a LOT OF RIBS. Most people eat 3-6 ribs (up to 1/2 slab).
Prep
Remove from packaging. Bam. No additional work required. If using foil trays, it might be easier to cut the slabs in half and lay with the bone tips facing down / rib arched up.
Oven method
300 for 6 hours(ish). Look for the meat to pull back from the bones. Lower temp is better (250) but can take much longer.
Smoker method
225-250 for 6-8 hours. As above, watch for the meat to pull back from the bones.
Serving
Be careful removing them from the tray, the bones may pull right out. Cut between the ribs if you want to keep them together, we usually make sections of 2-3 ribs. For kids, just remove the bones and the meat in the middle is super tender.
Leftovers
Deboned, it's basically pulled pork. Excellent in sandwiches.