what do you think about "menu on the master page" project

What do you think about implementing a custom menu (with links) on the master page, i mean the menu will be placed on the master page. The menu items will be populated from a list from the site. And the menu layout and look should be customizable through a css

How long do you think it will take a beginner (me:)) to do it and pls help me if u have any ideas

Thank you