The Kindle was made for narrative books, to be read end-to-end, one page at a time. Reference books like textbooks were not designed to be used that way, so they don't really fit the Kindle model. For that, we need something different. We need a reference ebook format, or at least some software that more easily allows flipping quickly to a page, cross-referencing, highlighting and notes, and multiple open pages (so you can simultaneously open end-of-chapter questions and the pages to which they refer).
Mokalus of Borg
PS - That quick page-flipping is a tricky one.
PPS - You don't always know the page number, and going one page at a time is a pain.