Using WWW or your naked Domain Name is something that has been a hot topic for debate over a number of years.
The literal or naked domain is the domain name that you probably use in your email address to the right of the @ symbol. Like wrenmaxwell.com.au
Personally, I have always tried to use and recommend that default business web sites should have www. Using the domain name only just creates issues with Domain Name Service management, particularly when the website resides on a server separate from other services for the same domain, like email. This view is supported by this response to the question at ServerFault https://serverfault.com/questions/145777/what-s-the-point-in-having-www-in-a-url
Suffice to say,
- YES, use www.yourdomain as your website URL
- AND, make that your preferred address for Google / Bing webmaster tools
- AND, redirect your naked domain so that end users who enter your domain name manually get redirected to www. This is important to ensure that you do not have duplicated content references to your pages.
- AND, finally, get an SSL / TLS certificate installed so that you are using https:// for your website