Check out this video about why and how students at a school in New York, started composting their lunchtime food waste.
If you would like to start one in your school, this slideshow by Groton will give you an idea who can be involved in it.
Mansfield Middle School in Connecticut even has a website to teach what composting is about. It is also touches on the variety of micro organisms that are beneficial to get a compost pile going. I think it is a wonderful way to pick up biology.
And if you considering a Vermicompost or worm compost, the website of The Adventures of Herman the worm should be a fun way to generate an interest of students in school to start one.
Don't miss out the many other useful information that you can find on Urban Program Resource Network. If you go to "Just for Kids", you will find the link to the award winning program, "The Great Plant Escape", where children can help Detective LePlant find clues that will uncover the importance of plants in their life.
Here is a good video of how you can start one at home posted on YouTube by : Kitchen Gardeners International.