If you already have your own domain, or prefer to use your registrar, the process of pointing your DNS record to your Shopify store can be confusing. In this tutorial screencast, Casey Whalen from our Support Team, guides you through the process.
Shopify also offers domain registration services, find out more under Domain Registration in the Wiki.
Casey is working on more screencasts which will be posted to the Build-A-Business Blog. If there's a topic you would like to see covered, please let us know in the comments.