Zend certified PHP/Magento developer

Setting up multiple sites correctly

I’m trying to set up multiple sites for my company.

We want to make it scaleable, so I don’t want to touch the default store. I want to create 3 stores, and each one of them needs to have it’s own unrelated URL.

Meaning:

http://brand-name-1.com
http://brand-name-2.com
http://brand-name-3.com

What should I use for the default URL? Do I need to buy another url (http://brand-name-0.com) and use that?

I don’t want any of the brands to have any relationship on the frontend.

Thanks