You can also find the Exam Thread list for A-levels here and GCSE here.
Just quoting in Puddles the Monkey so she can move the thread if needed
You should be able to find the specification for the exam on the exam board's website. This will give you a list of topics which you should have studied over the course. You'll find that essay titles tend to be based around one or two of these topics, so it's a good idea to try to write essay plans for each of the topics.
Hope this makes sense - feel free to PM me if you would like more specific help!