Add WP post to Facebook

I know it is possible that any time my boss makes a post on WP, that it can show up on his Facebook page.
Here is a website that has done it, so I know it works. I just don’t know how to do it.
http://www.golddustdental.com/blog/
The above site has a post on March 22 (scroll down to the lady with smiley face) that is also on their Facebook page.
http://www.facebook.com/pages/Gold-Dust-Dental-Lab/70377756861
When you view their Facebook page and scroll to March 22 you will see the same post as their WP blog.

Can someone please help a newbie out?
Thanks for any input.