Parents need to read this

Ask Dr. Sears.  Here's the blurb on the Discipline and Behavior page.

Discipline is more about building the right relationship with your child than using the right techniques. You want to put into place a guidance system that keeps the child in check at age four and keeps his behavior on track at age forty, and you want this system to be integrated into the child's whole personality, a part of him or her.

Here you can find what he thinks of spanking.  There are two other articles in that section that I think are pretty good, too.