I'm applying to a Christian college in my area, and part of the application process is to write an autobiography that outlines certain aspects of your life, such as your childhood, influences, religious upbringing, when you were saved, where you are in your relationship with Christ, and other various topics. My question is, what kind of format should this paper be in--i.e., do I put a title on it, what kind of structure should I use, etc. Hope this makes sense--and also hope I'll be able to clarify if y'all don't understand!

I would recommend, for a college application, that the paper be written in MLA form. You can reference the Modern Language Association Handbook (5th ed.) for information on writing MLA papers.

In college, you will have to write papers in this form, so why not show the admissions office that you can do it already!

As MK mentioned, there are two MLA books: the MLA Handbook for Writers of Research Papers (for high school and college students) and the MLA Style Manual and Guide to Scholarly Publishing (for grad students and professional writers). Here's a site with a little info:
What is MLA Style?

You should be able to find those books at libraries and bookstores.

Here's a great site that gives specifics about MLA and ALA styles (paper format, citing sources, etc.): Guide for Writing. (By clicking the "Return to Library" link, you can read sample student papers.)