Adding additional fonts

How do I add additional google fonts? I am using this snippet in my functions file. I tried adding an additional font line but that doesn’t work (breaks the site) I also tried duplicating the snippet with a different font which also breaks the site.

add_action ( ‘wp_head’ , ‘my_google_font’);
function my_google_font() {
?>
<link href=’http://fonts.googleapis.com/css?family=Raleway&#8217; rel=’stylesheet’ type=’text/css’>
<?php
}