The best way to prepare for a psychiatry exam is to read all your notes taken during the course, review any chapters you have read, and work with other students to quiz each other on material. Your instructor may give you guidelines or hints as to what materials may be on the exam, or you may be given a study guide to help you. If you need help understanding certain concepts, and none of these methods work, you can also search for tutorials online. These often explain detailed or highly complex concepts in simple terms, so they are easier to understand.
In most cases, you will have an idea of what will be on your psychiatry exam. If it is covering just a chapter or two, you have a more narrowed focus and will probably have worksheets or review notes to study from. For larger midterm or final exams, you'll need to look through more materials to determine what it is you need to study. Many instructors give worksheets or study guides to let students know what to read, but this isn't always the case. When in doubt, read through all the chapters and written materials you have covered up until that point in your class.
Writing information done can help many people remember concepts more easily, so it may be wise to copy information from your book onto index cards. Go through any chapters or handouts which might be included on your psychiatry exam, and copy down crucial information. Doing so will refresh your memory so that you recall key concepts, and you will also be forced to read materials more slowly as you write them.
Once you have the index cards written, you can continue studying for your psychiatry exam by meeting with other students. Bring your cards, and have your study partners ask you questions based on the information you've written down. If there are particular areas you are having trouble with during this study session, you'll know what chapters or sections to read back over. Then, ask your classmates questions for them to answer, since reading back over the materials as you do will also help with memorization.
You should also make sure you don't wait until the last minute to begin studying. This is a complicated subject, and your psychiatry exam will probably include a lot of complex questions. You may also have to remember the names of pioneers in the field, the names of conditions, and other key information. This is not information you can expect to understand after a quick read-through, so give yourself several days of study time, if possible.