It takes about 8 hours to cook a 7lb pork shoulder in a slow cooker. You can either put the pork shoulder in the slow cooker whole, or you can cut it into smaller pieces before cooking. If you choose to cut it into smaller pieces, make sure that the pieces are all about the same size so that they cook evenly. There are lots of different ways to prepare a pork shoulder in a slow cooker. You can either cook it with barbecue sauce, or you can cook it with salsa or other Mexican-inspired flavors. You can also use different types of seasonings, such as garlic powder, onion powder, cumin, chili powder, and smoked paprika. Experiment with different flavors to find the ones that you like the best. When the pork shoulder is cooked, it will be very tender and juicy. You can either shred it with a fork or chop it into small pieces. Serve it with rice, beans, tortillas, and salsa for a delicious meal.