There is not official standard dealing with the layout of about boxes, which display the credits of a computer software and other information.
What should a good about box contain? And... is it okay to put an easter egg in?
(source: seasip.info)
Looking at a few examples of About boxes:
These days, it probably wouldn't hurt to have a way to directly go to the website for the software in the About box itself.
Microsoft's Windows Vista User Experience Guidelines tend to have useful information on designing good user interfaces. I wasn't able to find information specific to About boxes, but the section for Dialog Boxes may be somewhat relevant.