I'd like to make a Orchard CMS website private and visible only to registered users.
Is this process similar to any other MVC 3 website by just editing the web.config?
Currently this hasn't been a scenario we've been aiming for specifically. You can of course make it work like any MVC 3 app, yes, but we're also adding the capability to configure it this way from the admin UI in the upcoming version 1.5.