Well, obviously, the menu access will be the easiest way to use it. A clever administrator might even work up a Cron job to print the information every night in order to document changes to the system. [Oh, wait a minute, I already did that.]
But there is another way to use this module. On one of my sites, I did actually document how to take over the site at such a time as I am no longer able, or willing, to do so. Before I wrote this module there was hard-coded information, for example, the modules in use, which was sadly out-of-date. With this module, I can insert a php snippet to invoke a section of the Site Documentation module to be included directly into the page.
<h2>Extensions to Drupal</h2>
<p>"Out of the box," Drupal is pretty powerful, but there were things we wanted to do with it that are not core functions. Drupal has a number of extensions (known as "modules") that we added to improve the site.</p>
<p>Additionally, we wanted to use the WebCalendar function to show our meeting dates and events. The Swap Shop section uses Noah's Classifieds. Both functions are also installed with Fantastico.</p>
It ends up looking like this (with my style sheets):