Hi, Mindi - it was nice seeing you and your family at the Bris on Sunday!
This is in response to your (actually, Michael's) question regarding parenting: "What approach would you suggest to deal with kids who keep nagging or act defiantly?"
A solution that works for us is our "F3" rule: Be Fair, Firm and Friendly. Do/say what you know is really best for your child's development and stick to your guns in a (sometimes almost robotic but) gentle way. If you use this rule as a litmus test when dealing with issues pertaining to discipline, it makes a huge difference.