Write out timelines for each major event so that you can get a sense of cause and effect. You can test yourself by later rewriting that timeline from memory. Highlight the different people involved in different colors. Flash cards are your friends. You have so many confusing terms to learn, that sheer memorization is going to be your biggest hurdle.
Mnemonic devices tend to work particularly well with science terms.
Practice is key. Read over your notes and become extremely familiar with the different literary terms and techniques that your teacher reviewed. Plot summaries are also useful. Finally, create a list of examples from each book that you are very familiar with so that you always have some material to write about. But if it's an essay or grammar test of some sort, then it's much more important to become familiar with the various verb tenses and conjugations.