It would be helpful if you edited your enquiry and put in the board that you are studying. Perhaps the people who wish to assist you can direct you to sources or give better suggestion beyond the generic. Also if possible what aspect of the preparing for history is given you a headache?
1.Memorising the facts 2 Academic Essay writing 3 Answering the question in the way the examiner requires. 4 Time management when answering a question in exam conditions so you finish on time.
Preparation for AQA A level with useful advice given by a teacher https://www.youtube.com/watch?v=lr6PcpTJPkk 1.Memorising the facts 1.Textbook/books flip through the whole book, then flip through the chapter, then leisurely read it. Then test your recall(how much you can remember) Go over it again before moving on. 2.Syllabus to hand make flash cards cover every point in your own words upto the first chapter. Write significant dates and names. 3.History Revision book read the section you covered before you go to bed or early in the morning. 4.Each day go through the Flashcards you need to remember them effortlessly