What should I be reading for my interview?

Don't bite off more than you can chew: compiling a huge, broad reading list will only stress you out and prevent you from actually exploring your subjects and refining your interests, which is the point of reading for your interview. Start with a few classics, or books that have always interested you, and see where they take you. For example, if you're reading for English, you might start reading Victorian classics, and really enjoy Charlotte Brontë's Jane Eyre. You might then decide to delve deeper into literature of this genre, style or theme, and read the 1966 novel Wide Sargasso Sea by Jean Ryhs, which was inspired by Jane Eyre, and other less famous novels by Charlotte Brontë, such as Villette. You'd then mention this interest in your personal statement, and the interviewer might mention it in your interview - you'd be prepared to discuss the topic with some insight because of the deeper reading you'd done. There is no need however to feel you need to become an expert - just showing that you act on your interests, and are reading voraciously despite school work should be enough.