How do I research my EPQ qualification?

Firstly you need to have a good question which you want to answer! This may sound obvious but think about it. If your question is too broad you will have to read too much stuff, you to specialise and have a very precisely worded question. Then you need to read around your question. Think about what you want to achieve with your essay. What do you think is the case? Why do you think it, and would you evidence this? You will need to then go and consult some broad sources, such as the encyclopaedia Brittanica or the Stanford encyclopaedia of Philosophy. You can cite theses in your essay if you wish, but the real reason for using them is that they have long bibliographies and lists of further reading. Check out whats on them and find things that relate to your topic. Read the essays, or the relevant chapters of books. Ask yourself: what is the author argueing, why are they doing? How does this relate to my question? Does it confirm or deny my hypothesis? Is it correct to do so? Depending on the outcomes you get from here, you then will want to consult the books or essays own bibliographies in order to find further reading. This should allow you to get a good amount of material together in order to argue your case so as to achieve an excellent mark.