Proper Config To Use www prefixed website address?

When you setup an account you just use the domain name, like somedomain.com. So email to anybody@somedomain.com is handled. I have the website (Wordpress) configured for somedomain.com instead of www.somedomain.com. I noticed that all my inbound links are using www. so I want to change my website to use www.somedomain.com. Just changing it in wordpress doesn't work as it appears Cpanel still redirects it since there's no www entry in the account config. What's the "proper" way to set it up? I want CPanel to serve the website at www.somedomain.com without any redirecting and want it to redirect somedomain.com to www.somedomain.com