Another www vs no-www question

I never realized that SEO could be affected by my interchangable use of www and non www urls with regards to my site and forum. I've often mixed the two together and now have realized that this can have an effect.

I read up on about which is better (either?) and ended up 301 redirecting all links from www to no-www, changed my vB settings (options ->URL) to no-www and also selected no-www as my preffered domain in Google webmaster tools. hopefully the 301s will change me over and unify my site into one 'site' rather than two and installing vbseo for the first time seemed like a fine time to make the change, right?

I had initally set up google analytics and webmaster tools from www and had to verify my no-www domain when making no-www my preffered domain. Fine, but now I have 2 'sites' listed in webmaster tools. Should I only use webmaster tools with the no-www profile from now on? My sitemap that was uploaded to www seems to also be accessible from no-www but I'm a little confused about whether or not I need to be updating both. Should I delete the www profile? Should I have just left this alone? (Not too late I suppose as I just made this switch last night).

I guess I just want to make sure that I'm doing the right thing by directing everything over to no-www, that I'm not fighting vbseos internal canonical rewrites, and that I'm not leaving a step out that could hurt my current Google standings.

Help for an SEO noob would be greatly appreciated.

Yes, you should delete the www profile. Making the non-www profile was not really necessary-- as you can still set the preferred domain within it to not have the www's.

I assume I have to add something to my htaccess file to force one or the other? Is any option better?

This is built into the htaccess by default, but it is commented out (and listed with yourdomain). You will need to edit it to your actual domain and then remove the hash mark.

For best SEO and the site actually functioning, these 3:

The htaccess file
The vboptions -> site url
google webmasters tools -> preferred domain

should ALL be set the same. Either with www's or without www's.

I personally do not use www's, as they as simply completely unnecessary anymore and is simply more typing. But, i made that choice 5 years ago. If most of your site is indexed with the www's, continue to use them.

I am using http://urltomysite.com everywhere,... would this be the correct syntax for the .htaccess file?

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

Yes, that's correct, assuming you are installed in /forums.