The Application Process

Does anyone have suggestions for books that they found really helpful when writing their essays?

I used the Stacy Blackman essay guides for every school that I applied to and thought they were awesome. Sample essays, very specific analysis on what a school is looking for as well as great advice on how to address the essay questions. Only problem is that they have guides for a limited number of schools - I lucked out that mine were available but I think they only have them for about ten schools.