OCR Computer Science book for GCSE here.
An excellent website for home learning 'Hodder Education' here
A very useful website with various resources for teaching the OCR GCSE computer science course "TeachComputerScience"
Another useful website for resources on GCSE Computing here.
A revision booklet for GCSE Computing Theory exam here.
A website with lots of resources on A451 here
A website where you can find GCSE Computing Quizzes Here