I have been reading around about issues where the se's weigh the www.domain.com and domain.com differently depending on how your site was indexed and on how your ibl's anchor text links.
I'm fearing that my domain, aarcmedia.com and a few others, might actually be suffering because of this and wasn't sure which I should 301 redirect to (the www. or without it)
Could someone please explain to me how this happens and explain how I can 301 redirect to the version of my domain that will rank better (if there is a problem at all?)
As for which you should redirect, if it's an established domain I would keep the one that has the most backlinks and google listings, and redirect the lesser known.
This issue has been beaten to death over the last year or so... and everyone has their own opinion.
The Big Daddy update was supposed to have taken care of this problem, and I have seen many cases where it has corrected it. But as we all know, Big Daddy has had it's share of problems. (losing pages, bad data pushes, etc...)
The main reason that it can be a problem is because if people link to your site with and without the "www"... you can get a split PageRank pretty easily. I would recommend that you go ahead and do the 301 so that the "www" is always forced into the URL... Better safe than sorry
As for which you should redirect, if it's an established domain I would keep the one that has the most backlinks and google listings, and redirect the lesser known.