5 Reasons Kids Lie: How to Teach them to be Honest. There are some really interesting thoughts here that make you take a step back to think about honesty and why kids might lie (or appear to be lying).
How to teach children to tell the truth. We can't expect our children to be honest if we are lying. Set a good example. We can't expect them to want to tell the truth if we scare and offer punishment. Discipline not punishment.