Notifications from Workbench included content type
You can do this with the Rules module: http://drupal.org/project/rules

It should be pretty straightforward, once you figure out how to use Rules. (You can find some video tutorials here: http://drupalize.me/videos/basics-rules-link)

Basically, you are going to create a rule that is triggered when a node's workbench moderation state changes. When the rule runs, it will send an email. In that email, you should be able to include tokens (http://drupal.org/project/token) that will be specific to the node that was just changed.

Hope that helps.