Best revision guides?Watch
For OCR History and Edexcel Maths, has your school given you textbooks? If so, I think they're the best things to revise from - especially for history. (I really wouldn't recommend the history CGP book, imo it's not very good compared to the actual textbook... maybe that's just me though). You could get a CGP revision guide for maths if you insist on getting one, but I haven't used that so I dunno.