Create a Custom Sidebar For Certain Pages

I’m creating a WordPress theme where I’d like specific pages to be linked with a custom sidebar.

For example I’m creating a page called ‘About Us’ and I’d like to create a sidebar for that page in the sidebars area called, ‘About Us’ that corresponds with the About Us page template.

Is this something I need to edit in my functions.php file? What about the original sidebar.php file?

I may need to create several sidebars in this fashion, however I’ve never done it before.

Thanks

-foo