Tough question. It's been awhile since my kids were in this situation, but this is what I can recommend.
Bottom line is that nothing works all the time. You will not be happy with the solutions that are out there.
Here are a few sites that will point you in the proper direction.
http://www.ftc.gov/bcp/edu/pubs/cons...ech/tec14.shtm
http://www.ikeepsafe.org/
The only computer side suggestion I have is to increase the security settings of the browser you are using and install Zonealarm.
Check with you ISP. They may have some suggestions.