i think chesskid.com is good.. no idea about goldchess though
Chess for Kids
why don't you have a look at this website: http://www.europechesspromotion.org/home-english.htm
My son Nathan adores it. There is a cat who explains rules and he can play online wit other kids. It looks like a very good program for kids...
I've seen chess for kids section in goldchess.com . What do you think about it?