Re: How do you study for MH?
Personally, I think you should start by making summarised notes according to the syllabus. Try to do this from as many sources as possible. Text books, notes, past papers, websites, anything that seems relevant and helpful. Make sure you get lots of nice quotes for all sections of your course, except maybe World War I.
After that, you should just read over your notes and try and memorise them. Make sure you know your time periods! Once you've done that for awhile and you feel confident, you should definitely try to do as many practice questions and past papers as you can and get your teacher to mark them for you. This might seem hard at first, but after you tackle a few of essays you'll find that a lot of the questions are quite formulaic and can be answered with pretty much the same information, just with some manipulation. For example, alot of the questions in 20th Century Germany on the Weimar Republic are all quite similar in terms of what information and what time period you need to focus your essay on.
You should also ask your teacher for any topic tests they might have. Try to get into a routine and stick to it as best as you can.
This is pretty much what I did, and it proved to be very successful. But with that said, everyone has their own way of studying, so you'll just have to try some of the stuff that's been suggested and see what works best for you. However, if there is one thing that I would recommend, its to do lots of practice questions! It will be immensely helpful in preparing you for the actual exams.
If you have any other questions feel free to PM me. Best of luck with all your studies!