How to add banner space right of header in new twenty twelve theme

I’d like to add a banner in the new twenty twelve theme header (to the right of the sites title/logo).

I’m using a child theme and would like to know the best way of doing this. Thanks!

[closed as duplicate – see http://wordpress.org/support/topic/how-do-i-add-an-image-logo-instead-of-the-site-title?replies=4 ]