Welcome to Sixu Hosting. One thing you will need to do is update your Nameservers for your domain at GoDaddy. The help file is located at the GoDaddy link below:

Got to: http://support.godaddy.com/help/article/664/setting-nameservers-for-your-domain-names

Click on "Setting Nameservers for a Domain Name Registered with Us"

In step 5 of the instructions, select "I have specific nameservers for my domains" and enter the two Sixu Nameservers provided in your welcome email under the "Server Information" heading.

Feel free to submit a support request if you need assistance.

Thanks for hosting with Sixu.