To give us an idea of the overall feeling of your brand, let us know which styles you lean towards
I think starting with a search to see home renovation logos is a good start—that's what comes to mind when I think about a logo. I think it should try to include different aspects of the application:
1) Grades (A, B, C, D, F) maybe showing going from bad to good
2) Test Score (472-528) again, showing bad to good
3) Essays (so maybe something with a typewriter, pen/pencil)
4) Maybe schools?