Is there a way to post a link to an outside website without creating a new post? Right now, my homepage is showing all of my post (great!), but I also want to post an additional link that is not connected to my site.
If that is not possible, can an URL link in the body of a post be active when it’s showing up on the homepage?
If you will put a URL inside post body it will strip your URL out of it because that’s how WordPress excerpt works.
However, there are other options:
You can place a link in the footer.php file or inside Widgets are by using Text Widget.
You can use plugin like Page Links To (http://wordpress.org/plugins/page-links-to/) and create post that will look exactly like any other post but it will link directy to any resource you specify.