How can I get colleges to send me books and info in my mailbox?

For NYU, I would say that big "Request Information" link right in the second links bar on that page OR in the giant purple print on the sidebar on the right side (right under the even bigger "Apply" link) would be the way to go. Most other schools have a similar option off of their admissions page, their front page, or their pages of information for prospective students.