data mining suggestion

Salam and hi

I am new to data mining and as well as with rapidminer. But data mining is getting interesting day by day. So i pay a good time to read the theory of the data mining. So as a result i have some knowledge but no practical use of it. As i am a software developer i made a school management software for a school where there is about 4000 students and 50 teachers. The software features result automation and the school admin asks for teacher's performance analysis. So now i have a data set and want to mine something from it but the problem is what can i do????????????????? I must add that i can get any kind of extra information from the student through the school admin

So I need some suggestion and how can i start, please help me...........................