WordPress MU

I want to make some blogs with wordpress mu and now i have two questions about it.

I have installed the multi-site-manager plugin, because i want to real domains as subdomains. It works, but i want instead of example.com that the domains were redirect to http://www.example.com, how could i do that?

Also i want to know, if it is possible to change settings in the main blog and so this new settings will also be changed automatically in all my other wordpress mu blogs?

It's not really an issue with the multi-site manager.
You need to search these forums for "adding www" to get the www back on your domain name.