Know Your Rights
Sexual harassment is illegal. The EEOC requires all organizations with more than 15 employees to have policies and procedures to deal with sexual harassment. Talk with your HR department to find out your organization’s policies. Contact the EEOC for the full legal definitions and a detailing of what rights you have. Knowledge is power- arm yourself before going into battle.
 
Say “No” 
Be sure to make it clear to the harasser that the behavior is not acceptable to you. Something as simple as saying "NO" or “That behavior is offensive” clearly, firmly and without smiling is enough to convey your distaste. Smiling, giggling or joking back will make the message unclear. There is a chance that the harasser does not realize the behavior is offensive and this may be enough to end it. If you decide to file charges later, it's helpful (although not necessary) to have objected to the behavior. 
 
Keep a Record
Keep track of what happens on as it happens (don’t wait a week or two to write it down) in a journal or diary by writing down the dates, times, places, others who witnessed it and description of the harassment. Keep any letters or other documents that may be involved.

Talk to Others
Unlike workplace harassment, harassment in the schools is usually more public. Maybe comments are made in busy hallways, or whistling occurs everyday outside the school (directed at whoever is walking by), or a hostile locker room atmosphere creates an uncomfortable feeling for everyone. If you talk to others you may find that they have had similar experiences and concerns. Your may also be able to round up witnesses who saw the harassment that was inflicted upon you.

Write a Letter
If you talk to a teacher or administrator about your problem, they may advise you to write a letter to your harasser. Many people do not realize that what they are doing is harassment because no one has ever called them on it before. A letter is also a good way to keep the matter quiet and between you and the harasser.  The letter should be calm and direct. Detail the behavior that you found inappropriate and refrain from emotional outbursts. Most often there will be no response from the harasser but the behavior will stop.
 
Report the Harassment

1. You first step should be to try and deal with your employers or school system. They are required to have policies fro dealing with sexual harassment. They should also have an appointed contact person trained in dealing with those situations. Identify that advocate and use them to help you file a formal or informal complaint with the company.
2. File a complaint with the state agency that deals with employment discrimination. You don’t need an expensive lawyer to start the complaint. The people you are dealing with in your company (or even your local research librarian) will know how to get the right forms. Some state agencies will automatically notify the EEOC of your claim.
3. As a last resort if your company is not dealing with your complaint, you can also file a complaint with the EEOC. Their purpose is to enforce federal anti-discrimination laws. If you think your situation may require legal action, make sure the complaint goes to the EEOC right away because they have short statutes of limitations (deadlines) for sexual harassment claims. If they find that you have a good case the EEOC may prosecute the case for you or will tell you to go ahead and start the legal actions yourself.