It's a word that can strike fear into the heart of the bravest site builder: Breadcrumbs. Manage them well, and you'll give visitors a helpful visual indicator of where they're at in your site. Miss a detail, and the weird inconsistencies will be more confusing than no breadcrumbs at all. The challenges stem from Drupal's "flat hierarchy" -- by default, almost all pages (including every node you create) live just beneath the home page itself in an undifferentiated pool of content. All of the visual cues it sends to visitors (breadcrumb trails, highlighted parent items in the navigation menus, and so on) start with that assumption until you override them. That's where the Menu Position module helps out. It lets you set up simple rules that tell Drupal where each node type should go in the site's hierarchy, then handles all of the frustrating details automatically.
The module's operation is simple and straightforward. Site administrators can set up simple rules describing certain pools of content -- nodes of type 'Blog,' articles tagged with 'Star Wars,' and so on -- then assign them to a particular parent menu item. From that point on, the rule will ensure that matching nodes get the proper breadcrumb trail, highlighted menu trails, and so on. Multiple rules can be active at once, positioning different pools of content in their proper home. It's a much more efficient approach than positioning each node underneath a parent item manually, and there's no performance slowdown if your site sports thousands (or hundreds of thousands) of nodes.
Menu Position was created by John Albin, the author of the popular Menu Block module. He's well-versed in the frustrations that come with wrangling menu items and breadcrumbs, and the module is polished and straightforward. The only downside is that items must be children of an actual Drupal menu item. If you'd like article nodes to appear as if they're the children of a complex contextual-filter-driven view, for example, additional modules like Path Breadcrumbs might be necessary. For the vast majority of sites, though, Menu Position module does the job smashingly, and with a minimum of hassle.
There is a Menu Position video on Drupalize.Me which shows how to use this module.