This cover reminds me a bit of the Dutch children's book "Een bezem in het fietsenrek" (A broom in the 'fietsenrek'). I can't find the English word for fietsenrek, but it looks like this. The story not about a high school at all, though :) Summary from the book cover, roughly translated:

When the witch Marijn finds a mail-order catalogue in her forest with images of all kinds of strange-looking devices and people who look very happy, she decides to venture into the world to become very happy as well. But because she doesn't know how the human world works, she experiences many absurd situations.