Review the material that you have covered. You may have more than one exam in the course of your class in keyboarding. If this is a final exam than you need to review everything, but if this is only on specific parts of the course than you only need to review those sections.
Practice your keyboarding. You can find sites in the resource section that will help you practice your keyboarding. There are games that can increase your speed and help you practice your keyboarding making it fun to study.
Build up your speed. There is a game, "Typing of the Dead," that will help you build up your keyboarding speed.
Keep in mind the posture you need to keyboard. Sometimes in a keyboarding class, the teacher will give a final exam to each individual at specific times rather than have the whole class take the exam at the same time. This way she can check your posture as well as your finger positioning and grade you on them as well as your work.
Make sure you are keyboarding accurately. This is a very important factor in your grade. If the teacher finds numerous mistakes in your work, you will not get a passing grade. Therefore, it is an important factor when studying for a keyboarding exam.