Just keep your links constant when you add back links to your site. If you use the www then every time you submit a link or advertise, be sure to use that. Then when the update happens, you will get your juice for the www.
That's the best choice to redirect one as it can affect your serps having two different urls indexed within Google that have exactly the same content and the bad thing about it is that it's your most important page, which is the homepage that is duplicated.