Here is Godaddy Instructions:
Thank you for contacting customer support. To obtain the authorization code for your .info, .us, .biz, or .org domains, please follow these directions:
First, log into your customer account:
• Go to the Go Daddy Home Page
• Click the "My Account" link toward the upper left corner of the site.
• Log in using your account username (which may be the same as your customer number) and password
Next choose "Domain List" from the 'Go To' dropdown and click Go:
You will then need to click on the domain. Above, on the green label "Domain Status Information" you will see in parenthesis "(click here to recover authorization info)".
Once you click on this, it will be emailed to your administrative contact. You will need to make sure that you do this for all the .info .biz or .us domains that you plan on transferring away from us.