Should my site start with www. and if it doesn’t will it make a difference?
When you set up your domain you need to make sure that the www. and the non www. version of your site points to the same location, you can do this via a 301 redirect which is normally done automatically via your host. So if a visitor types in your address with or without the magic www they are redirected and the www. will automatically appear in the address bar, if this doesn’t happen you need to fix this asap.
Without a 301 redirect Google will look at your www. and non www. version of your site as two independent websites, beware as this does not mean you double you chances of getting to Google top positions it has the opposite effect and a chance Google will penalise you for duplicate content.
Check your site redirects: type in http://example.com and http://www.example.com in two separate tabs in your browser and check the address bar. If they are both the same you already have a redirect set up.
If they are different go to your host, manage your domain settings and set up a 301 redirect for the site you do not wish to appear in the address bar, (normally the http://example.com address) if you are having problems with this is may be worth contacting your web developer or your host directly.
Alternatively contact us firstname.lastname@example.org