AS-Level English Language Complete Revision & Practice by CGP Books
This book is full of clear revision notes and exam-style practice questions covering every topic for the AS English Language course. The whole thing's designed to make revision straightforward - everything you need to know is explained simply and thoroughly, including all the important terms, research and theories. There's also a useful section on how to do well in your exam and loads of coursework advice. It's exactly what you need to prepare for your exams.