When you register a domain name with a registrar, you will need to set the name server associated to your domain name to a nameserver, so that the Internet can relay to the correct server. The nameservers for Big Kahuna Hosting is:
NS1.BIGKAHUNAHOSTING.COM
NS2.BIGKAHUNAHOSTING.COM
You'll need to enter both. Each Registrar is a little different on how you do that, but it should be relatively easy to figure out, or call their support for advice.