I marked the other as resolved since did not know how to close or delete it.
I am using WordPress 3.4, turned on networking, installed 'WordPress MU Domain Mapping' version 0.5.4.2 and followed your instructions as best I could since the menus were different, and have my basic or first site working Ok.
When I login as admin, I see "My Sites"/Network Admin with Dashboard, Sites, Users, Visit Network but do not see any Super Admin menu though do see admin is a "Super Admin" from the Users' tab.
I do not see the "Super Admin" tab with Domain Mappings and domain tabs like in your example, but do see a Settings tab with Settings, Domain Mappings and Domains.
I don't see any Tools menu for the Network Admin dashboard nor a Tools menu on the Dashboard for a particular site that has a Domains Mapping submenu.
And when I select Settings/Domains in the Network Admin dashboard, I am asked for a site id. I just picked number 2 and managed to add a new domain but what number to use was not intuitive though I saw my first site was #1 hovering on some button.
So I have two sites defined and only my main site (e.g. MyFirstSite.com) works, and it happens to also be my GoDaddy shared hosting site URL.
So I am unclear what I need for the second domain site in terms of a virtual directory at GoDaddy, a real directory in the file system under the root, or as a path in WordPress multisite. I did set mapping to the actual URL of the second site (e.g. MySecondSite.com) but if I do the dashboard or visit that site I get a 404.
Also don't know if I'm supposed to check "Update siteurl and home as well" (I did check that) or am supposed to have a path of "MySecondSIte" in the site info as well (I do have that), or have a real such folder under the root, which I do have, though nothing was put into it.
Thanks so much, Dave