How can I put the Subscribe by Email form in the header of my WP site.

I want to put the form up in the header of http://www.hrhound.com and keep it really small. Basically I just want the email address field and the submit button, side by side horizontally under the coffee cup.

Right now I can't seem to find any shortcode and then I'm not familiar with the formatting needed.

Many thanks,

Alvin