Just a quick question: In Google Webmaster tools I have my site set to set to www. and the naked domain.
Do I need to add and verify the site for each variant or do I just keep it as the www and use either reference? thank you!
While it is not necessarily needed to add both the www and non-www versions of your domain for webmaster tools to work; it's a best practice to add them both and then set you're preferred domain (www or non-www) under Configuration > Settings.
It's also a good idea to use the canonical tag in your site to bolster you're preferred domain settings.
Yes, we recommend adding both versions: http://googlewebmastercentral.blogspot.de/2008/10/wheres-my-data.html
One of the main reasons for that is that it makes it possible to check the data for the "non-canonical" version. For example, if you choose to index the www-version, and others have linked to the non-www version (naked domain), then having both versions verified would allow you to see those links directly.