I'm a newbie in need of some guidance...
I have several commerce sites. I want to create a social networking community and have it be interactive with my commerce sites.
Specifically we're intending to do several Blogs, multiple Chat rooms (both public and private) and a Question/Answer site. We'd like it to look like our existing commerce sites, so that users moving back and forth between the social network site(s) and commerce sites are unaware they're leaving one and entering another. And most importantly, we want users to create a login (user/password) and have this single login give them access to both blogs, commenting on blogs, and chat rooms. (I want to avoid captchas... they're personally frustrating for me, so I don't want to force them on all my users.)

None of it needs to be really elaborate... straightforward. Simple. Easy to administer and manage. Easy to get up and running. There are 2 of us doing this and we're both computer savvy, have built websites and built computers, but neither of us is a programmer and we want to be able to (for the most part) install and manage it ourselves without needing to hire programmers every time we need to make a change or add a function.

Help. there's so much out there and the more we try to figure out what to do the more bogged down in the decision we're getting. I just want to get to the blogging part!

Just use something off the shelf , search at website like hotscripts.com ,etc .

Your best bet is to post in our Existing Scripts forum (within Web Dev) asking if there are any particular CMS solutions out there that fit your bill. Specify whether you are looking for a Windows solution (i.e. Community Server for .NET) or a PHP solution (WordPress and vBulletin both come to mind).

I think you should check with wordpress plugin for chat system, hope this link would be helpful to you; http://wordpress.org/extend/plugins/tags/chat

I recommend checking into Joomla or Drupal. They are both open source CMS.

I am using wordpress for something similar and there are a number of other CMS systems that would allow you to do this also.

Be aware that if you go with WordPress and you choose to host it through WordPress you will have to pay a minimal yearly fee to supress ads showing up on your site (WordPress free hosting of sites will put ads on your pages). The other option is to download the WP software and put it on a server you are in control of.

Also, there are available plug-ins for Wordpress that enables you to add chat and add more CMS components to it.

There are also a multitude of themes, a lot of which you are able to alter the color and appearance if you know a little about CSS. WordPress is a very good option.