The New York Times has a five article series on their choice blogs, or something like that, written by Dean Fitzsimmons that talk about admissions at Harvard. It’s quite informative. This is the one that talks most specifically about the admissions process: http://thechoice.blogs.nytimes.com/2009/09/10/harvarddean-part1/#more-7513
When taken with @gibby s information, it’s probably fairly helpful. At least, I found it to be.