Try to research there https://adwords.google.com/select/KeywordToolExternal?defaultView=3 but I don´t know what you mean "tutoriaux"
Education, at least in theory, will always be a good niche just like health because these are everyday issues and a lot of money involved.
BUT ... how should i know if it work? kashifmahmood Try to do some experiment . Write an article of both and see if they are really worth it