I think the top four things I would want my students to know about Digital Citizenship are:
1) How to keep themselves safe...not posting information that will allow them to be identified and tracked, 2) The responsibility they have for information that they post and the awareness that just because they can say it on the internet doesn't mean that they should. They need to understand that what they put out onto the web is there...permanently, and it can be damaging to themselves or to others, and 3) That just because the information is on the web, doesn't mean that it is reliable. They need to read carefully and evaluate their sources, checking and cross-checking to make sure what they are reading is indeed correct. This is a big one for my students because they struggle with reading anyway,and 4) there is an etiquette to using information that is posted on the web. They need to understand how to give credit for work done by others that they access whether it be print, picture, or video.
I really like the Brain Pop movies on digital citizenship. They have activities that can be printed out and completed as the movie is watched or afterward that will allow me to check my students' understanding of what they have seen. I think for my parents, I would create a form that discusses some of the main points of digital citizenship and attach it to a contract for them to complete along with their student. I could then keep those contracts. Once the students and parents have completed everything in the digital citizenship workshop, the students could receive a certificate signifying them as digital citizens.