Setting up user rights/permissions

Hi All

As you can see I am very new here, so Hi!

I am building a school website using Drupal but am having problems setting up the user rights/permissions.

There are 4 users, anon, web editors who maintain the site, teachers who maintain the class pages and admin the forum and pupils who contribute to the forum.

I am really clear on how to set up the forum rights and permissions but am struggling with the following;

How do I set up web editors to be able to create Teacher Users, Same for Teachers setting up pupils but not web editors.

Also, how can I get Teachers only to have access to admin their respective Class page (ie year 1, year 2 etc...). Thanks