The most important employment issue that you always need to keep in mind is the issue of legal (or "authorized") versus illegal (or "unauthorized") employment. You must always make sure that any employment you plan to engage in is legal employment. Any unauthorized (i.e. illegal) employment - even for one day - even if you did not know it was illegal - poses a grave threat to your ability to remain in or return to the United States. And you must always make sure that you have the necessary employment authorization before you begin work, since starting work without prior authorization-even if you receive authorization later-constitutes illegal employment.
You should always consult with an OISS adviser before beginning any employment. This is the only way to be sure that you won't engage in illegal employment, with all of its adverse consequences for your future in the United States.
Definition of Employment
Employment is any type of work performed for services provided in exchange for money, tuition, fees, books, supplies, room, food or any other benefit. If you receive no pay or other benefit for the work performed, this activity is not generally defined as employment, but can be considered to be volunteer work.