Be revealing. You don't have to be explicit, but it's important to reveal truths about yourself and your life in an autobiography. Don't let the book become a list of your accomplishments, with all the negative material carefully kept under the rug. Present yourself as a whole person, sharing talents and flaws alike, and your readers will be able to identify with you and hopefully root for you as they make their way through your story.
Create an outline or a graphic organizer of the major topics and ideas you want to cover. For example, you might make a time-order chart -- a chart with event blocks to organize events chronologically. Or, you might draw a cluster web -- a diagram with connected circles -- to divide your autobiography into sections, such as one for relevant background information, one for life-changing events, one for special memories and one for goals and dreams. Focus on reasons why specific events, situations and circumstances were important to you and how they made you feel.