What would a good unit on "Digital Citizenship" include/look like?

As I have increasingly added the use of Web 2.0 tools and Internet research to my classroom lessons, I have found that my students have absolutely NO idea that just copying and pasting anything from the web and using it as their own is wrong! 

I have decided to add a quick (my classes are only 42 minutes long!) day lesson in the first week on proper use of Internet resources, copyright and plagiarism.

Tell me what KEY things (1-3 under each of these topics) you would be sure to include if you were teaching this.  I have some ideas but want to see if I've got any glaring gaps based on what you tell me.  Remember...I don't have long to "teach" these basic ideas so give me the big ideas you think I MUST get across to the students as we begin the year.

Thanks in advance for your suggestions!