Database design

hi i would like a database designed similar to a blackboard.
requirements:
Login page
the module leader has transparency of everything
supervisors for the module are allocated and have allocation slots for students which reduce in number as a student is accepted by that supervisor
students can upload work
supervisors can exchange marks between themselves for similar work
supervisors and students can communicate from the same area like a private message?
announcements from your specified supervisor

there are a few more add ons to this once we get the ball rolling.