It's a good idea to educate one's own children and not let the government do it.You are going to tell them the truth i'd think.
In my house Jack Herer's book "The Emperor Wears No Clothes" is required reading.

By the way I am a pot smoking daddy....well accept on saturdays when I don a dress and some pumps and put on a little make-up...err ...I guess i'm still a pot smoking daddy.