Is it possible to add a new subscriber to my current current list? I was looking all over the place for a way to do that but couldn't find anything.
Hi wickeddiana (nice name!). Sure, adding a new subscriber is pretty easy. If you go to the manage subscribers tab and pick the list in question you'll see a link that says 'Add or Remove Subscribers'. On this page you can either manually add someone or import a file. Just make certain that the individual did explicitly ask to be contacted by you about the topic at hand.
In addition, you can always add a subscriber form to your website that will automatically add subscribers to your list. On the same Manage Subscribers page click on 'Create a Subscribe Form' and that will give you the code to insert on your page.