Menus are configured at Admin -> Customizations -> Menu Manager and are marked in templates with <!-- BEGIN MENU MENUNAME --> areas. These are the menu item template variables which you can use in any menu in the templates:

{MENUITEMLABEL} - The label (aka title or name) for the menu item which will be shown to people.
{MENUITEMURL} - The URL of the destination page the user is taken to when clicking the menu item.
{MENUITEMACTIVE} - True if we're already viewing the page of the menu item, otherwise false (for use in conditionals).
{MENUITEMISFIRST} - True if it's the first item in the menu, otherwise false (for use in conditionals).
{MENUITEMISLAST} - True if it's the last item in the menu, otherwise false (for use in conditionals).