The Boston Public schools have a very nice cyber safety program with a home on the Internet. This site has resources for teachers, students and families. These resources include posters and presentations that can be downloaded and used. While they are clearly branded for the Boston Public Schools (BPS) the themes and information is universal. There is some really good stuff and the bright colorful graphics (characters were designed by students by the way) will appeal to younger students.
Also if you are interested in Internet Safety you can use the Internet Safety tag on this web site to search for other information that I have posted in the past. Or use this link (Internet Safety) if reading using an RSS reader.