It happens quite often, that we have to work with Drupal sites, which were started by other companies or Drupal developers. In the beginning it's quite difficult to say what's going on with the site; how many modules are involved, how many custom content types etc. The more functionality on the site - the more complicated an upgrade/enhancement/re-branding can be. The more room for some potential issues/inconsistencies, the more pages to theme etc. This is where the Site Documentation module can become very helpful. The module exists not only for Drupal 6, but also for Drupal 5.
Basically, the module collects the information from various sources (mostly the database), and appears on one page. You can set which data to report. You can also collect the reports via cron and archive the output HTML files to disk for future review. Hint, this can save your day when you're trying to figure out what was changed and when. (aside of your subvertioned code). I will not list everything that the module can collect - However, I really hope you will try to install it yourselves - or you can read more on the project page (http://drupal.org/project/sitedoc) or in this nice article (http://nanwich.info/drupal_collection/site_documentation_module/intro).
Here are just some features that I like the most:
- you can see the content (with html and php code from the database) of the custom blocks created via UI ('boxes');
- you can see (and easily compare) the visibility settings for the blocks, including pages where it should be shown or php code;
- not only can you see the Drupal settings, but you have links to most of the admin settings pages - all in one place!
- the Webserver and PHP information can be collected and archived
- useful when you need to compare some environments
- past and current, or deployments on different servers I think that the Site Documentation is a 'must have' module and will help you see the bigger picture!