Obtain a list and picture of the cranial nerves. You will need a list that tells the number, name, function and location of each of the 12 nerves. The picture should be of the underside of the brain and show where each of the cranial nerves comes out of the brain. There is a good example of this picture on the Neuroscience for Kids link in Resources below.
Create a mneumonic that you will remember that helps you memorize all the cranial nerves in the correct order. One mneumonic is: "Oh Oh Oh, To Touch And Feel Very Good Velvety Soft Hands." You can personalize the mneumonic to be something that is easier for you to remember, though.
Study the picture of the cranial nerves and where they come out of the brain. Knowing their origins will assist you in being able to identify the nerves in a lab practical situation. It will also help if you study the nerves on both the picture and on the cadaver. For example, Cranial Nerve I (CNI) is the olfactory nerve. It comes from the olfactory tract and olfactory bulb located on the inferior frontal part of the brain.
Learn the function of each of the cranial nerves. Note if each one is sensory, motor or both. Each of the cranial nerves varies in its function, so it's important to learn which one performs which function. For example, CNI is a sensory (afferent) nerve and serves to provide the body with a sense of smell.
Synthesize the information so you make it applicable to human anatomy on the whole. Memorizing the information will get you so far, but you must understand how it's applicable in terms of function to really understand how the cranial nerves work. Take a look at the Neuroscience for Kids link in Resources. This tells how doctors test the 12 pairs of cranial nerves to determine if a person has neurological damage. Learning how practical tests work and which nerves they test will help you synthesize the information and therefore understand it much better.