In this example I'm using the 'Racing Sans One':
First off, hit the 'Quick Use' option in Google Fonts, this will give you a URL to link into your header.
Instead of linking the URL open it in your browser:
This will give you the following code that you can then copy and paste into your .css file:
font-family: 'Racing Sans One';
local('Racing Sans One'),
Note: The 'local' attributable checks if font is on users local device. This is great for development. However, it's not bulletproof. See:
...for more info on how to fix this during production.
You can also download any Google font and embed from your web server as .ttf by adding:
To the stack above.