Webmasters, one thing that you must be aware of is canonical duplicate content penalty and how to avoid it.

To avoid Canonical Duplicate Content, you must make sure that the search engines don't see your Domain as, www.yourdomainname.com and yourdomainname.com, because it will be treated like two separate Domains. All of your pages could, then be considered as duplicate content and that could hurt your search engine rankings.

The best option that you have, is to do a 301 redirect from the www. to the non www. or from the non www. to the www.

This tool generates code that will need to be added to your /.htaccess file. You will need to create one if it doesn't exist. For more information how to create a .htaccess file. Please read, How to Create a .htaccess file.

Canonical Duplicate Content Fixer Tool: