Haha no worries. I took maths, bio, chem and physics. Initially dropped physics but took it up again to keep engineering as an option.
Yup, sat them all in June, which looked like a nightmare in the weeks leading up to it, but if you take each day at a time, and plan out exactly what you need to cover each day leading up to each exam you'll be fine.
I didn't have a revision timetable (can't stick to timetables :P) but I did follow the specification very closely in the last few weeks and wrote out everything in the textbook again in my own words.
There are a few model answer documents that usually fly around exam time and basically has all the model answers to typical content questions. Learn them, but be cautious cos they're really trying to trip people up nowadays with questions.
I did use a few revision guides but that was to summarise and help recap your learning - sometimes Its hard re-reading the fat OCR books, especially if it's the day before the exam and you feel like you've read it a hundred times already..
When exam season started I re-did my notes on powerpoint, with each slide covering a specification point for each exam in a subject. The slide had everything that specific point covered. I had like 40 - 60 slides at the end of it for one subject! I'd print off all the slides for a specific exam 2-3 days before it and use blu tac and stick them to the wall on my room, so, literally everything I needed to know was in front of me, all the time
I made sure I revised in my room and whenever I had a question I'd just look up at my wall and find the answer! It worked best with keywords and definitions.
I'm not saying do what I did, but try something that works best for you, experiment with things during your mock exams in december/january and perfect your revision technique.
PS: If you're interested, I'll try and find a couple of the powerpoints I used when I'm back home again. I did Edexcel biology, but you might be able to use the slides as reference or at least follow it if you think it works for you