The three things that I would be most concerned about would be:
-not giving out personal information
-never downloading anything without permission
I like the Brainpop and NetsmartKidz tutorial and also the I-SAFE lessons tailored to each grade level to use for instruction on digital citizenship.
I would use these tutorial periodically to reinforce the idea of digital citizenship with students. I would also include parents on some of these sessions and have q and a sessions with them. I think the I-SAFE lessons in Spanish would be particularly effective