The iPad has some Restriction Settings that you can take advantage of to limit access to applications and services. For example, you can disable Safari (web browsing) the Camera or FaceTime. You can also filter the Internet and block access to sites like Twitter and Facebook.
Please note that if you choose to enable iPad Restrictions on the iPad while the student is at home, that you turn these restrictions off when the child takes the iPad back to school. You may want to consider enabling these restrictions when your child first gets home from school and then disabling them in the morning before they leave for school.
iPad Single-App Mode
You can also lock the iPad to a single application, such as iBooks, so they can read books, but not surf the web or play games for example.