How can I create another menu after the homepage?

THe home page has my main menu.

How do i create another menu. So that when you click on a main menu item, you go to another page that has a second menu. Then that menu leads to an article.

You would use the menu module appropriate for your target phone.
We'll use the Main Menu module for mod_mj_pda_menu. Copy this module and open it.
Give it a different title and enable it.
On the right in module parameters select the menu you want to use.
Lower left, select where you want it to show.
The above assumes you already have a site that you want to convert for mobi use