Adding a Content Item to a Menu
There are two approaches for adding items to menus: you can use the menu administration form to create a new menu item, or you can create a menu link from the content item that you wish to reference from within the form used to create or edit that content item. The best practice is to use the content creation form or other element creation forms such as a panel page or a view. The reason for using this approach is that when you delete that content item, Drupal automatically removes the item from the menu to which it was assigned. If you use the manual approach of creating a menu item using the menu administration form, you as the site owner must remember to remove that item manually from the menu.