How should I revise?

It is dependent upon the course and whether you need to focus on Language or Literature. One of the most important things is to become familiar with the material. For example, if it is a book it is vital to understand which scenes would link to a specific exam question. Another important skill would be to become familiar with language terminology because this would benefit you not only in English exams but in your other exams. I would also suggest perfecting a format in which to answer different styles of exam question.