I think the most important thing in this subject is constant revision. I'll try and explain kind of elaborately but this is important.
Week 1 - A
Week 2 - B
Week 3 - C
Week 4 - D
Imagine each letter is a seperate section of the AOS, for instance A is Bloody Sunday and B is Witte's reforms and so on. In school, you will be taught these things sequentially, and at the end of the AOS you will be marked upon it by a SAC. Now, the most dangerous thing (which was my downfall, I speak from experience) is simply moving on and letting go of what you have learnt. You need to read back over old notes every week. From that, you will absorb all that knowledge into your long-term memory. Come exam revision time, you will not be learning the course all over again but you will be doing checkpoints and past exams - which is the only, ONLY, way to do well in the Revs exam.
Pardon the long winded post, but I believe it's really important in life to learn from other's mistakes. Yes, History resources are scarce. The only (easy) way to get exams would be from your Revs teacher, if you go to a better off school this will be easy. If you went to a shit school like me you'll be given 1 trial exam and told good luck.