Try this site, it’s kind of simple but might help. Otherwise check out some books in the bookstore or library.

http://www.sarasota.k12.fl.us/bhs/bryan/bryan_auto.html

Here’s more info from a specific college…

http://www3.shastacollege.edu/eops/SPRING%202007/Scholarship%20Guidelines%20Handout.pdf

Try to think of a single, highly charged emotional experience you’ve gone through. Imagine you’re watching a movie and you want to be drawn into the story right away. But have this “scene” be a reflection of some aspect of yourself. Set this scene at a specific moment, with specific people. But be truthful. Then begin a more generalized treatment of who you are and what led to that moment and surrounds that moment you have already described. To repeat: BEGIN your story this way, don’t lead up to it. Make the scene so interesting that your reader will want to continue reading. It’s just as important for an autobiography to be interesting and entertaining as it is for it to be truthful. But do stick to the truth as best you can.