In this recipe, we will first populate our main menu with sample menu items by creating some basic page stubs. Following this, we will learn how to create a submenu block that will display a submenu generated from the main menu items.
For this recipe, you will need to install and activate the Drupal Menu block module: http://drupal.org/project/menu_block.
This recipe also assumes that you have the Bartik theme installed and set to default. If you are not using Bartik, simply select a different region for your block in step 19.