3 things I want my students to know.
1) There are people out there that post as other people other than themselves to get information about them. EX: an older person posting as a kid their age. NEVER talk to anyone you don't know!, we always tell children that. Well, now with our digital world, it goes beyond that as I mentioned before.
2) Password safety: Always create a password that is something very personal to you. Something that it's difficult to guess. There's another kind of people called "hakers" this people like to get into people's accounts to steal information (this will be useful for them as they get older and get bank accounts and important things like that)
3) Last but not least, know your source. There are many ways to tell weather a source is a credible one or not. For educational purposes, always go to websites that have an .org, .edu or .gov at the end. this way you know that the information that you are getting is reliable. .com means commercial meaning anyone can post anything without being researched or revise by anyone before posting as "a fact"
Source: A good resource to go to for digital citizenship is The cool Cat teacher blog. She has a good explanation and a very useful chart that it's easy for students to understand.
How to teach it: A discussion based class, showing the chart from the Cool Cat teacher blog and showing a poster that I have about Internet safety rules.
Sharing with parents: It is very important for parents to know what is going on now in our cyber world. If I could, I would like to hold a personal conference with the parents to explain to them how easy it is for children to get into the wrong sites, to get talked into giving information to strangers and everything mentioned above so that they can practice and re-enforce this rules at home.