Mission Chicago South Shore Medical Marijuana Dispensary, one of the few dispensaries on the South Side, is building a classroom to be used for marijuana education, adding registers and planning to double employee count to 20 by year’s end, said general manager Rick Armstrong. It’s also changing the shop’s setup to be more self-serve, arranging the products by type — topicals in one section, edibles in another. Customers will come in and see cards describing each product, like in a wine shop, and take that card up to the register for checkout.