http://www.lsa.umich.edu/english/grad/howtoapply/lang.asp
I followed these guidelines:
Clearly labeled academic & intellectual Statement of Purpose: up to two pages, double spaced, statement about your academic and research background, your career goals, and how Michigan's graduate program will help you meet your career and educational objectives. Disregard the 500 word limit as stated on the application. Clearly labeled biographical Personal Statement: up to two pages, double spaced, statement about how your personal background and life experiences, including social, cultural, familial, educational, or other opportunities or challenges, motivated your decision to pursue a graduate degree at the University of Michigan. This is not an Academic Statement of Purpose, but a discussion of the personal journey that has led to your decision to seek a graduate degree. Disregard the 500 word limit as stated on the application.