GCSE Bitesize Revision Guide: slanted directly towards the skills needed for the GCSE exam
Shmoop guide: these are always entertainingly written. There’s a very strong American bias, but it’s an American novel, and you’re studying this as part of the ‘Other Cultures’ strand of the course, so maybe that’s a good thing in this case.
Sparknotes: another US based study guide, with a strong section on context.
Heald English 