folks: The main site is pointed to mydomain.com I have

Hi folks:

The main site is pointed to mydomain.com I have a redirect set at the hosting provider to point http://www.mydomain.com to mydomain.com (is that the best way to do it for SEO and properly)?

Or, should I remove that and do it on WP somehow (if so, how)?

Lastly, when using http://www.mydomain.com it works good. But when I go to http://www.mydomain.com/subpage (or any page other non home page) it reverts back to http://www.mydomain.com home page only. How can I fix that?

Thanks guys.

Greg