Are you aware of the guide to acing exams?You can stop thinking about spending for that.You can do it on your own.You should categorize your lessons so you can organize them accordingly.A great help if you can also make your own illustrations. This is what you call visual aid.Now, you should learn to speed read.Allow your brain to process texts in blocks.If you have nothing to do you can get some book.This will make speed reading easier.If you are going to have an exam, try to focus your self on that alone and not on other things.If you follow the acing exams guide then I am sure you will get that great grades. You know it is really easy to ace your exams. Just learn how to focus!