An autobiography by definition is an individualized account of your life and who you are as a person. However, there are a few things it should include to give the reader some sense of who you are and why you have made certain choices.
The introduction into your autobiography should include a broad picture of how you see yourself, to include what makes you happy and how you see the world. This will give the reader a sense of how to incorporate your life story into your perception. One of the best ways to do this is to include a brief summary of your home life, such as your parents, siblings and the environment you were raised. This allows the reader to self-identify with you.
After you have established a baseline, you should incorporate major life events or challenges and how you dealt with those situations. For example, you might describe a particularly tough sports loss, dealing with death, going to college or being fired from a job. You can draw parallels between your childhood, other events and your point of view to explain to the reader how you handled it.
Finally, as you complete your autobiography it is important to give the reader a sense of where you are going in life. Describe your goals and how your past will assist you in reaching those goals.
Remember when writing an autobiography the stories should interest the reader through humor, fear or self identification.