This website is a useful source of information, with links to Edexcel the awarding body and the publishers.
For a Gateway page with links to lots of useful stuff see All about SNAB
Salters-Nuffield Advanced Biology is context-led. What is meant by this?
In many biology courses, the biological concepts are presented, and examples or applications are given at the end.
Salters-Nuffield Advanced Biology introduces a context and then presents the biological concepts needed to understand what is happening. This makes the relevance of the biological knowledge immediately apparent to students.