When it comes to what to teach kids about money, there are some great resources out there beyond the Money and Kids site.
One of the best resources out there are the columns of Janet Bodnar which appear in Kiplinger's Personal Finance magazine as well as on the Kiplinger website. With 20 years' of writing about kids and money under her belt, she has a wonderful background in cutting to the chase. I'm betting having three grown kids helps, too.
These really are just the highlights. Be sure to read the whole article for even more information including some additional resources related to financial education for kids.