While the Internet is a valuable tool for children, they don't always understand the dangers. It is critical that parents teach kids about online safety and responsibility.
Make sure the computer is in a common area so you can monitor your child's usage. Allow it to be used only when a parent is home.
Initiate a set of rules regarding use of the Web, and review them frequently.
Install a content filter that regulates which sites they can visit.
If you allow your child to have a MySpace page, insist his/her profile be made private. Ensure that you are allowed to view all activities.
Limit the amount of time they spend online.
Test your children. For example, have someone contact your child online posing as someone else to see how they'll react.