Just buy the cahier du jour cahier du soir which is what the French kids use as revision guides. The class of 6 eme is for 11 year olds in France, 3eme for 14 year olds. (costs about£5 on a famous internet site. Grammar, texts, exercises etc) You won't be doing any more than that in A level, and then just watch as much French T.V as possible. For essay practice use étudier.com. There are literally thousands of sample essays on it used by french kids to pass their exams from GCSE level through university and beyond. You can have access to free material,pay for full access or submit an essay to gain access to all materials. Definitely worth looking at.