It's a simple problem, but a serious one. You've put your content editors in front of Drupal for the first time, and they can understand the node form without any problems. They understand taxonomy terms, grok menus and node references… but they get nervous when it's time to save their work. "Will... will this be published as soon as I click 'save?'" Normally, there's no good way to make the distinction between saving and publishing a piece of content explicit. Site builders can set a content type to be unpublished by default, then give editors the broad "administer nodes" permission, but that's clumsy solution that forces editors to dig for what should be a simple action: publishing or unpublishing a post. That's where the Publish Button module comes in.
With the module installed, every content type gets a simple new checkbox: "Use publish/unpublish button." Once it's selected, users with appropriate permissions get a new, Publish, on the node edit form. It unambiguously flips the node's "Published" flag and saves it. If the node is already published, the button reads (predictably) "Unpublish." Site builders can set up fine-grained permissions around who can and can't publish and unpublish content. Setting posts to be unpublished by default, then enabling this module, can give the Drupal content creation workflow an almost WordPress-esque simplicity.
Because Publish Button is so simple, there's not much to say about how it works. You set up the permissions, activate it for the appropriate content types, and you're ready to go. It won't solve all of your content workflow problems -- it makes no provisions for scheduled publishing or detailed review of revisions, for example -- but it's a clean, quick solution to the uncertainty that comes from Drupal's one-size-fits-all "Save" button.