Use the SCS essay guide which you can purchase for 30 cents at the SCS reception desk. His book goes beyond just writing the essay and gives excellent tips on the application process in general. You may find this book in the Graduate College office and the Student Counseling Service Library, or you can purchase it at the University Bookstore. You will want people who have seen your performance in different settings. You may want two from faculty and another from a work supervisor.
Research shows that recommendations from high profile faculty are very valuable.
If you do not know any professors, make an appointment with professors in which you have received a good grade and share copies of your old papers or tests. If you have not been in school for a while, ask the graduate school about what type of letters they prefer. In general, waiving the right to see your letters increases their credibility. February 1 is a common deadline for applying for financial assistance. Be prepared to complete more than one per school, because sometimes the department and the graduate school want their own copies.