Various ways to present a larger amount of information on one page, and let the user navigate amongst it:
JqueryPP.com has a fucking OUTSTANDING table-of-contents. Try playing with it... scroll up and down, and notice how the left-side changes as you scroll, particularly regarding how sub-sections are displayed.
For implementation details, see application.js (search for "menu") and CanJS
zoom to subsection
zoomooz.js — pretty cool