How do I add a copyright to my website and what does it mean planetbouncerentals.com?

You can put a simple notice at the bottom of each page that says that all content is the copyright of planetbouncerentals 2008. If you want, you can add something to the effect that any breach of copyright may be pursued in law. It depends on how 'heavy' you want to be and what you're protecting. The copyright usually lies with the creator of the website and/or the owner of it. Asserting it by putting a notice at the bottom of the page emphasises that right.