Warehouse associates can have a wide variety of duties on any given night. If you're good at one job, they'll train you in another. For the most part, however, warehouse associates load and unload trucks, sort smaller parcels by location into larger bags. They also offer hazardous material training if you're so inclined. UPS generally does not in hire full-time, so warehouse associate is the most accessible way to a full-time position. The shifts may only be 4-5 hours long, but UPS makes sure their employees earn their keep.