The duties of support staff are, for the most part, assigned by academic building, with most having a half-time secretary. Faculty in the sciences can also call on several people who support work in the labs and who help take care of equipment. Part of managing our own time involves making full and efficient use of the people whose job it is to help us out in support of the educational mission of the college. Most of us come to a new teaching job without much experience in asking for help from secretaries and other support staff; it's one more thing to learn how to do. Ask people in your department, and others in your building, for ideas on the kinds of tasks that can be delegated. Ask the secretaries and lab techs themselves. Don't be shy about asking if a particular job is appropriate or feasible to the talents and time available of the person. But do be thoughtful and considerate when requesting work to be done. Give explicit, written instructions, including an indication of the day and time by which you need the job done. If it's a rush job, ask first if the person can fit it into their schedule, and if they can't, do it yourself. (So it's to your benefit to think ahead!)
Most departments also have student workers who can help take the load off the building secretary for some tasks. Ask the chair of your department for information about this person and their schedule.