Method

Mix all the rub ingredients together and store in an airtight container. You will use this in the brine, to season the meat, and once the meat is cooked.
Place the pork shoulder in a large enough bowl to hold both the pork shoulder and brine. In a separate bowl or jug, stir all the brine ingredients together and pour over the meat. Cover and refrigerate for at least 6 hours. For added flavor, allow to brine overnight.
Preheat oven to 325°F.
Remove the pork from the brine and pat dry. Place the pork in a baking pan (fat side down) and sprinkle generously with the rub mixture to cover the entire pork shoulder. Leave 3-4 tablespoons of the rub for use after the pork is finished cooking.
Place the baking pan in the oven and allow to cook for about 6-8 hours or until the meat completely falls off the bone and shreds easily. If the pork shoulder is less than 7 pounds, cook the meat at 325°F for the first two hours and reduce the heat to 300°F for the remainder of the cook time.
Once the pork is cooked and tender, shred the meat. Do not remove any juices from the pan. You should work the juices into the meat as you shred. Discard the bone and skin. Once the meat is completely shredded, sprinkle with the remaining rub mixture for added seasoning.