The resource I recommend the most is the SNAB Biology A Revision Guide. Slimmer than the standard textbooks, this revision guide includes concise yet accurate notes on topics 1 to 8, tips on how to improve your exam skills & technique, and a good amount of sample questions to test your knowledge. You may have noticed that the SNAB papers’ mark schemes contain points that are not included in the original textbooks; whatever is not included in those books are included in here. This is why I would say it is essential to study through this book alongside the other textbooks if you are aiming for an A*/A grade. Click here to buy the SNAB Biology A Revision Guide from Amazon UK for £8.48.
Another great asset to your studying is the SNAB Biology A Revision Workbook. Given the limited availability of original exam questions, this workbook is a lifesaver for developing your answers. The workbook offers worked examples showing you how to structure your answers, many exam-styled practice questions with answers, and even features 4 timed tests across all topics (which are unique to the workbook). Click here to buy the SNAB Biology A Revision Workbook from Amazon UK for £7.38.
CGP have a great reputation for revision guides and this occasion is no exception. The CGP SNAB Biology Revision Book covers every topic from both years of the course. It’s fully up-to-date for the new exam specifications for 2015 and beyond, with straightforward explanations, helpful examples and full-colour diagrams throughout. Practice questions and exam-style questions (with answers) are included for every topic, and the book is rounded off with a section of in-depth advice on Practical Skills. Click here to buy the CGP SNAB Biology Revision Book from Amazon UK for £19.99.