@iclearwater,
Roberta and Centrox are correct. I would just add two things, while the expression is mostly used for someone in charge to a subordinate, the most common use is for a child in the presence of a parent or teacher.
Second, another use of the verb "mind" is somewhat opposite-to be annoyed by the behavior of someone else. Thus, a polite person might, when a chair is missing from the table at which he is to sit at, go to another table that has several chairs and only one person sitting and ask, "Do you mind if I take this chair?"