As a cleaner, it is your responsibility to ensure the building or buildings you're in charge of are spotless. From sweeping the floors and washing windows to cleaning the bathrooms and maybe even mowing the lawn, your goal is to make the building(s) shine.
A lot of your job is done after hours usually, as that's when everyone has gone home and will be out of your way. Some of the work may be unpleasant since there will be areas that are more dirty than others.
Luckily, the job isn't too demanding education wise, so you should be able to pick it up after a bit of on-the-job training. Other than training, you won't need any formal education. Another plus for this position is that you can essentially work anywhere. Everyone needs an exceptional cleaner.