Sorry for late reply. I made quite a few notes for topic assessments and that helped at the time so I'd say notes are really helpful. Get a decent text book or revision guide for your exam board because some seem to be a little different. If youre struggling with programming, going over simple exercises before going back to harder ones youre doing for homework or for exam prep could be helpful. Also comment any code you get given to work on! It will force you to understand how it works and make answering questions and updating it so much easier.
Another thing to think about is exam technique. If you have access to past papers use them. Check examiners reports. Plan how much time you need to take in each section before youre in the exam if you can.
Another tip that has helped me with all subjects is revise to understand rather than learn. Obviously you dont need to go in to any more detail than what given to you but i mean when learning something like the fetch execute cycle try to understand the purpose of each step and how they link rather than just PC +1 then MAR does this then this does this ect. with out actually internalising what it means.