To check if you have a www/non-www canonical issue perform a site: search in Google-
site:http://domain.tld
The above search will find all pages indexed under the domain including the www and non-www versions. If you have a small site look through what is indexed, if you find both www and non-www pages indexed you have a canonical problem.


open your .htacess file and to some type:

RewriteEngine On
RewriteCond %{HTTP_HOST} !^yourdomain\.com$
RewriteRule (.*) http://yourdomain.com/$1 [R=301,L]

Don't know if it makes much diff. but I have 50 sites and all are non www seems to work fine and reads easier in serps.