Kristen Howerton, blogger at Rage Against the Minivan, has a great article, How to teach kids about race, I highly recommend it. In her article she speaks of the mistake that so many white parents are making today,
"What NurtureShock discovered, through various studies, was that most white parents don’t ever talk to their kids about race. The rule is that because we want our kids to be color-blind, we don’t point out skin color. We’ll say things like “everybody’s equal” but find it hard to be more specific than that. If our kids point out somebody who looks different, we shush them and tell them it’s rude to talk about it."
I experienced this first hand one night while in a room full of white people, except for one man, a friend of mine. In normal conversation, I said something to the effect of "well [my friend] is not white so he may have had a different experience." The room filled with nervous laughter, and "Oh mans", the basic feeling was that I had insulted him...by stating the fact that he was not white. This article was so helpful for me to see that although I hadn't insulted him I had shocked the other white people by speaking about race, not just in the abstract but in the here and now.
Click on over and read the article, it has great advice for how to raise children who will actually see diversity as a good thing to be embraced and celebrated and not a secret :).