Hi Angie,
As soon as you publish your site to the web, it is automatically protected by copyright. In fact, as soon as put any thoughts down in writing, they are protected by copyright. You no longer need to get an official copyright; in fact, for a website that is regularly changing its content, trying to go through the process of an official copyright each time you made a change would be very time-consuming!
You can, however, use
Copyscape to help protect your site. They even have a banner that you can put in your footer to try and discourage people from stealing your content.
The only thing to consider is a way to prove that you had the content first. But honestly, if someone steals your content and you call them on it, they're most likely not going to challenge you.
Hope that helps!