If the site is small, and you just need a multi-level menu that gets displayed on all pages, you may:
- Insert it as html code (<ul><li><a href, ... etc) somewhere in template.php
- If you prefer the menu to be editable in the admin interface, do the same but by adding a component.
- If you'd like to be able to edit it in the admin interface without having to know/use html code, with the rich editor, you may put the menu in a private page, then include it in template.php (
see this post by n00dles101)
Of course you have to put titles, paste page links, etc. and those won't change automatically if you edit the titles in the Page editor -- you have to do it manually. If the site is very small maybe it's ok, but if it grows...