internet safety

With all the hype regarding social networking and online collaboration what does a parent need to know to ensure cyber safety for their children? As a parent of a tween and teen I am constantly asking myself, "do I know what I need to know to support their Internet use?"  

I believe the first thing that each parent should ask themselves is "where is the home computer located?" Is it in an open area of the house for all to see or is it in a room that can be closed off from other users? Our family took the plunge and bought a laptop- the kids can take it "anywhere" but "anywhere" in our household is typically the kitchen or family room where everyone has a clear view of the computer and the sites being accessed.