Pulled pork is most often made from the pork shoulder butt (sometimes called a Boston Butt). It can be prepared in the oven, in a slow cooker (crockpot), or in a smoker. If you are preparing a whole pork shoulder butt you may want to use your oven. Most people don't own smokers, or a crockpot large enough to properly cook a whole shoulder butt. The meat may be marinated for 12 to 24 hours prior to cooking. Try marinating in this: 2 cups Orange Juice, 1/4 cup lime or lemon juice, 3 tablespoons minced garlic, freshly chopped thyme, salt and pepper. Tip: Pierce the meat deeply with a fork a few dozen times to help the marinade absorb into the meat.
After removing meat from marinade lightly pat dry and coat with a pork rub. You can find ready made pork rubs in the spice aisle at your local supermarket. Place into a deep roasting pan preferably with a lid. If you don't have a large pan with a lid you can use aluminum foil to to cover the roast, be sure to cover pan completely. Place into a preheated 275 degree F. oven. Roast for 5-8 hours dpending on size. 3-4 lbs for 5 hours, 4-5 lbs 6 hours, 5-7 lbs 7 hours, 7-9 lbs 8 hours. Remove from oven and let sit for 15-20 minutes. Meat should easily shred apart when using a fork to pull meat off of roast.