Here were my thoughts from 11.5 More Things in 2010 about digital citizenship: http://agalnamedal.blogspot.com/2010/06/thing-11-digital-citizenship.html
I still agree with all 5 of the topics that I suggested in my 2010 post. I really want my kids to take pride in the work that they share online and in the classroom, but I also want them to be safe out there as well. Etiquette though is still something that my students need to work on. I don't think many of the parents at our school monitor their students' internet behavior, so it's important for teachers to be the models for the students.
I like the questions posed on this site: Moving at the Speed of Creativity
I would devote a class period at the beginning of the year to working our devices, digital citizenship, etc. I would use the questions to brainstorm with the students in regards to safety and talk about the etiquette involved in using the internet. I usually send a paper home at the beginning of each semester with classroom expectations for parents and students to sign and keep a copy. I could include safe practices in it for parents to read or add onto my school webpage.