It took me ages learning, this, so i know how frustrating you are finding it.
Don't recognise that page at all
Scott was very surprised when i could not get cname records sorted easily, can't remember his exact words, BUT
Here goes, if you have yourdomainname.com with registrar ie Register.com
And your website is hosted with ie GODADDY.COM you change the DNS records to i suspect something like ns1.GODADDY ns2.GODADDY (possibly ns3.GODADDY) now i used godaddy as example i know you have something with them, but there dns may be something different but it usually follows similar name.
You domain is now hosted with register.com but you can then go to godaddy and either add on the domain or park the domain with them because the website itself is on their server.
ADD ON points at your website
Parked is slightly different, and on some hostings :: Blue host, just host you can park all your domains so that one website in the rute of your hosting appears as though it were each individual domain.
With S DRIVE what we appear to be doing is parked
Now i hope Scott jumps on me quickly if I am wrong, but i think this is why the advice in CC is to change CNAME records rather than dns records. (UNLESS BOUGHT THROUGH CC in which case they will automatically be parked.)
lets clear up 2 things
(1) is Register.com your account, the clients account, or the original designers account
If it was me doing this (i did this for wedding car site) I opened his own domainmonster account, with his own username password etc, and once it was all set up, gave him control, incase anything ever happense to me, and the same with CC account he has his own copy of VSD log in etc.
(2) do you want the .us .info . net you bought all looking the same, because i dont think in s drive it will work as such, so if you add say .us to CC sdrive account the others will have to be pointed using a re direct from Register.com (UNTIL CC GET THEIR HOSTING COMPLETED)
you can still call if you want help, just sitting in watching the box