How do I revise for this subject?

You have to remember that English literature is about argument and interpretation. Read a text thoroughly, write down the main themes you find, the quotes you feel are important and characters you find interesting. Look at what critics have said, do you agree with them? You have to keep on top of notes, maybe create some flash cards to help you remember your original ideas. Keep on top of quotes and remember to reference and challenge other people - just because a critic has their opinion published doesn't mean you have to create your argument in agreement with them.