Yes. Basically, when you create your content it should include this information for the Kindle to really handle the content well. This enables things like quick navigation (the bar at the bottom of the page that allows the user to switch between chapters and such).
We create all that content low-level and it isn't all that complex. But the easiest way (if you only have a few documents) is to use a tool such as MobiPocket Creator to create these files.
EPS Software Corp./ CODE Magazine
We can help you put your books/magazines on Kindle