Budd:e, an interactive e-security "game" from Australia, is a great tool to add to your online safety toolbag for students. It offers both primary and secondary versions. It is not a tutorial itself, but rather tests students' knowledge of appropriate ways to ensure their online safety.
Primary students build a "Budd:e" by answering questions related to, for example, digital citizenship and cyber-safety. Secondary students run through a series of real-life scenarios (you've received a message from an unknown person on Facebook asking for pictures) and choose appropriate responses to deal with the situation.
UPDATE: Yikes! I just realized I forgot to include the link. My apologies!