BBC Bitesize Computing and Other Resources
It would be worth looking at the BBC Bitesize homepage for computing. There are lots of classroom resources and activities here, suitable from Key Stage 1 through into secondary school. If you are looking for a starting point to design a computing lesson, you might well find one here.
Other excellent resources include:
Barefoot, from CAS. Aimed at primary children this package of resources has also been used lots with lower secondary students.
Rapid Router from Ocado Technology, which helps students develop computational thinking and programming skills step-by-step.
Digital Schoolhouse, which includes projects linking to computing in creative ways.
Computer Science for Fun (CS4FN) from Queen Mary University London. These resources take a different perspective on computer science, covering interesting applications in the real world and fascinating stories.
Why not use the discussion on this step to recommend resources you have found useful?