How to make sub menus on the homepage main navigation

I have a lot of links and was wondering how I would make submenu on the main navigation? They’re currently being displayed when you click on a page with submenus but I want quick access from every page

http://partners.sbceo.org/volunteers/

Hello lRlevolution,

When you hover on main menu like Programs, Educators, Business etc., sub menu will be change which is showing in yellow background.

Please confirm if this is what you required exactly?

Thanks,
Manish

YEs this is what I want. so that my main navigation has sub-menus