I have read almost every post in these forums about nameservers and DNS settings and I will never be able to accomplish it unless I actually understand the process. If someone can confirm whether or not I'm correct in the following please do so:

DNS works like this:

1) End user types in a domain name eg. www.mydomain.com in their browser

2) The request goes to the registrar of the domain name

3) The registrar checks which nameservers the domain name point to and forwards the request to the appropriate nameservers (in this case nsx.servermatrix.com)

4) Servermatrix holds a record of each and every domain associated with its nameservers and then forwards the request to the actual IP/address

So, this is why we go to our registrar first, assign the nameservers and IP's, next we tell Servermatrix through the ticket form that we want the domain name to be included in their record database and after a few days everything maps to the appropriate place.

Once this gets clarified I can continue to append my second DNS related question.

I think this will explain it better than I could.

Yup, that's the plan. Of course, I always submit to the registrar the change of the DNS first since it takes over 24 hours for anything to happen then go over to my server to get the account set up then have SM add that to their name server. All done in under 10 minutes so it does not actually matter on the order.

Great, nice article btw...here's the subquestion:

Pointing a domain to a site set up through WHM...again, do all of the above and also contact SM for the addition. Now, Servermatrix is sending the request for this domain to my single IP address. My server knows which folder/website to show through the setup in WHM by the domain entered for the site, correct?

Correct - when you create a site in WHM it adds the dns entries automatically (so if you ran your own nameservers you wouldn't have to add them to servermatrix dns manually) and also adds the correct directives to the httpd.conf file so apache knows what to do for the domain in question. If you're curious, take a look at the end of your httpd.conf fille after creating a couple sites.

Perfect, thanks for clarifying everyone.