In this section, we’ll be adding resources for early secondary school-age, or ‘seniors’, or key-stage 3, that is approximately ages 12-14.
The only series that I’m aware of that covers most subjects at keys stage 3 is CGP, Communication Group Publications. I have to say that I am not a fan of CGP books at all, but they do have the advantage of being relatively cheap and easily available.
Otherwise it’s a case of finding resources for different subjects piecemeal. Letts covers the core subjects of Maths, English and Science for example but not much else as far as I’m aware.
See the individual subject pages for specific recommendations.