Also don't rely wholly on controls/supervision. Talk too, have casual conversations about the dangers that can be caused by contacting strangers over the net, about the exploitation that goes into making certain types of videos, about the fact that you can get a criminal record purely on what you watch/download online. I don't mean sit down and have The Talk, more get into the habit of having open conversations about how the world works and gradually slipping this information in.
DD starts at secondary in September and my parents have bought her a laptop. They haven't given it to her yet but I am concerned about safety and controlling its use a bit. We will set up the BT Internet parental controls to a high level. Do you control the amount of time/location of use/check the search history etc? What tips/rules would you share?