Schema / Whiteboard architecture for app/db

We need to work out what the architecture of our app is going to be, and we plan to whiteboard this. Once we have this whiteboard plan we'll translate it to a more internet friendly format to put in this issue.

EDIT: We slightly underestimated how long this would take, we have created the DB plan and the user flow, but not a fleshed out architecture, in the 2hrs. I think a total of 4hrs will be more than enough though.