The most important point to remember when cooking a prime rib roast is to ensure that the meat is not overcooked. Marbled steak cuts, like the prime rib, need some extra vigilance when cooking on the grill because their fat content can cause flare ups.
At least three hours prior to cooking, remove Prime Rib Roast from fridge and place on a rack inside a roasting pan. About 30 minutes before you start cooking, preheat the oven to 450 degrees F. Plan out your cooking schedule so you leave ample time to cook your prime rib roast to your preferred doneness.
You will want to estimate about 12 minutes per pound of meat for the cooking time. To calculate cooking time, allow minutes per pound for rare and minutes per pound for medium rare. Cook the prime rib to 115°F for rare and 120°F to 130°F for medium — remember that there will be carryover cooking as the roast rests. 
Cooking a boneless prime rib is easiest to cook and easiest to carve. However, the bones do add flavor to the meat and protect the meat from overcooking. So, the best way to prepare the roast is to cut the bones off prior to cooking and tie them back on. I salt the roast generously all over, and the bones, then place the roast back on the bones and tie it together with cooking twine, one tie per rib.
