In many cases, interested high school students can find summer or part-time employment in the janitorial trades. High schools, college dormitories, and apartment complexes often hire extra custodial help during the summer months.

Other sources of learning about janitorial and maintenance jobs are high school shop courses, which help students prepare for the variety of maintenance tasks that custodians perform in their jobs. A familiarity with cleaning tools and materials, whether gained through part-time employment or through maintaining one's own home, should prove helpful as well. Students might talk with a janitor at their school or apartment building in order to find out more about the job, or visit the Web site of IEHA (formerly known as the International Executive Housekeepers Association).

Janitors perform a wide range of jobs, using equipment that varies from simple mops to power tools for making minor repairs. They are responsible for selecting the proper methods and equipment to clean and maintain the structure in which they work, whether it's a school, shopping mall, hospital, or hotel. Their specific duties may vary somewhat, depending upon the type of building for which they are responsible. Their job description may include sweeping, mopping, waxing, and buffing floors; vacuuming carpets; dusting furniture and handrails; washing walls and windows; cleaning bathrooms; and collecting and disposing of trash. They may also be responsible for some low-level maintenance and repair work, such as fixing leaky faucets; monitoring heating, cooling, and electrical systems; and exterminating pests or arranging for a pest control worker to do so.

In some cases, janitors perform outdoor maintenance. They repaint units, repair broken signs or landscaping, recaulk windows, fix holes in parking lots or sidewalks, or replace locks. They may also shovel snow or apply salt or sand to sidewalks in the winter and mow lawns and trim shrubs in the spring. Some janitors have duties that are particular to their workplace. For example, when schools close for the summer, their janitors work on the grounds, make minor repairs, and sanitize the building to prepare it for the next year. They also maintain and repair the gymnasium floors and test and service the heating and cooling systems. Janitors who work for apartment buildings or complexes may be responsible for dealing with residents' complaints or needs and, in some cases, collecting rent. Those who work in hotels and motels change linens and make beds in addition to performing regular cleaning tasks. Janitorial workers in hospitals, often called central supply workers, clean, sterilize, and assemble hospital equipment, supplies, and instruments. Similar duties are performed by laboratory equipment cleaners in other industries.