The best way to help at an international school, if your children attend there or if you live nearby, is to volunteer your services if you are a fluent speaker of English and of the native language where the school is located. Volunteering to tutor or to act as a translator for students and parents can be appreciated. Although there are staff available at an international academy or school, your expertise with English and with American English and customs would prove valuable to the international academy.
A school, for example in Greece, that is an international academy and may be a residential school and an English school, will have a staff made of teachers who know English as a second language. Or, they may have some native English speakers, but your fluency in English, especially as spoken by an American, will make your volunteer services really special.
There are many people who live in foreign countries who speak only American English. They probably use the services of a nursery school or of a secondary nursery school located in the area where they are employed. Your volunteer services at a nursery school with the children of native American speakers of English will make your place in the secondary nursery school or in a nursery school that advertises itself as an English school important.
If you are wondering how to volunteer as a tutor or a volunteer mentor at an English school in an international academy, the quickest way is to visit the school with a typed resume and leave it at the front office. If you include that you are willing to work as a volunteer tutor with children who are fluent in both English and the language of the country that you are living in, you will surely be called upon to offer your assistance. Until you are called, you can drop off magazines and newspapers if you get them mailed to you from overseas. Staff working in a residential school that is also an international academy would love to have access to media that you might be getting from your family living overseas or from your contacts.
If you are looking to help at an international school, consider what areas you are better suited at like language tutoring, media, or volunteering during holidays that may be celebrated in America and not in the country where the international school is located. An international school service that places teachers and tutors in schools around the world is ISS. International Schools Services has lists of openings and job placements. They can be found online.