Originally Posted by Brujah

I have this setup and testing multiple domains from 1 admin. I'm moving old wp sites and some small static sites into the new wpmu installation. It forces you to strip the 'www' but sends a 302 redirect so your listings should remain.

This has been useful:

Plugin: Redirection
Manage all your 301 redirects and monitor 404 errors
http://urbangiraffe.com/plugins/redirection/

Plugin: BuddyPress
Adds additional social networking like features and a central navigation bar to manage your blogs. Helpful with multiple authors.
http://buddypress.org/download/

More plugins that you may be interested in using here:
http://wordpress.org/extend/plugins/tags/wordpressmu
http://wordpress.org/extend/plugins/tags/wpmu