Help Wanted: Top Right Header Dropdown Menu

hi,
on my website i have 1 main centered header menu. i also have a top right menu. i can add tabs to top right side with a widget.
i added my cart, my account, and customer service tabs with this code.

(i replaced a’s with @’s to show you the code)

<@ href=”#”>My Cart <@ href=”#”>Customer Service</@> <@ href=”#”>My Account</@>

i want to add to customer service tab sub menus like about us, contact us, and policies. and i want it to be hover over dropdown menu

how can i do that? please help