What are some of the topics you have studied? I would recommend you select the topic in which you were most interested. You are certainly more likely to be engaged in the effort if you select the topic that most interest you.
Oh, and do NOT do like one student in Tech School tried: He plagiarized from the book the teacher had written! No, he was NOT the brightest bulb in the bunch!
No, he was NOT the brightest bulb in the bunch! 
