Hi, Nick,
Welcome.
Yes, there is an admin area to add courses. If you have installed Moodle successfully, you can go to the front page of your new site and log in. Moodle will know that you are the site admin. You will see the administration menu over to the left. You can add courses, add users, edit site variables, etc., from there.
You will find all the additional information you need to get up and running with Moodle right here: http://moodle.org/doc/ . And in these forums, of course.
Hope this helps,
Art