Firstly, follow the instructions in the article on setting your WebStore Live
However, if you have not changed the Name Servers and www.my-domain.com has been aliased to nscstore.nitrosell.com; You will need to forward the root of your domain to www.my-domain.com via your domain control panel.
For example, if you bought your domain through GoDaddy you can follow the steps below to forward your “naked” domain (without the www) to your NitroSell WebStore.
Type your domain name with the www into the “forward to” field, and click “Add”. Set the other fields as pictured.
A message will pop up warning that the changes could take up to 48 hours; however, in most cases it will take much less time.
IMPORTANT: You should NOT point your domain to the IP that nscstore.nitrosell.com resolves to. This IP is subject to change!