The Sub-page module gives Moodle course design additional flexibility in creating nested activities and organizing resources on their own page. If you’ve ever used Blackboard for course creation you’ll be very familiar with the concept. Sub-page is developed/maintained by the Open University for Moodle 2.1+ but has not been officially released to the Moodle.org plugins database, but as you can see from Mary Cooch‘s video could be used now in testing (at a minimum).
Give courses a little more depth in structure and organize resources/activities a click away from the main page.
Mary’s original post: http://www.moodleblog.net/2012/01/14/sub-page-module
Youtube Video: http://www.youtube.com/watch?v=T3lynb89BeY