Customize the link and logo on the WordPress login page.

custom_logo_link.php

// Use your own external URL logo link
function my_url_login(){
    return "http://www.carriedils.com/"; // your URL here
}
add_filter('login_headerurl', 'my_url_login');


// Custom WordPress Login Logo
function my_custom_login_logo() {
    echo '<style type="text/css">
        .login h1 a { background-image:url('.get_bloginfo('stylesheet_directory').'/images/My-Logo.png) !important; 	}
    </style>';
}
add_action('login_head', 'my_custom_login_logo');

Carrie - if you want the site's front page to be the url in your first function, you can use this instead of hard-coding it:
return siteurl();

Useful gist, by the way. I was having to do this for a project this week.