Documentation for aliases, primary domains and redirection

I have been testing Mercator on a new multisite setup and would like to see some more detailed documentation around aliases and the correct way to set a primary domain. At times I see sites enter into a redirect loop and think I am most likely doing_it_wrong.

Right now there are 4 places a domain name can be set within the network admin:
- The info tab (which I am guessing has to remain as the sub-domain/sub-directory on a multisite e.g. mysite.multisite.com)
- The site settings tab (which allows you to modify two site options for `siteurl` and `home`. I am guessing these should be set to the primary domain, e.g. mysite.com).
- The aliases tab (which allows you to map other domains to your site. e.g. mysite.com and mysiterocks.com. If mysite.com is set as primary in `siteurl` and `home` I would have thought that mysiterocks.com would redirect but it does not. All aliases work standalone).

So my questions are:
1. What is the correct way to set a new primary domain
2. How do I get other domains to redirect to the primary domain to avoid duplicate content

Thanks