This is a wonderful Australian website with sections for 'young kids' (0-7 years), 'kids' (8-12 years) and 'teens'. Within each section is a wealth of resources including information, games, quizzes and videos.

http://www.cybersmart.gov.au

There are resources for parents, teachers and libraries as well.

Young kids can visit the circus:
http://www.cybersmart.gov.au/Young%20Kids.aspx

Kids can help to stop cyberbullying and do a quiz to see how cybersmart they are:
http://www.cybersmart.gov.au/Kids.aspx

And teens can look at the pros and cons of social media:
http://www.cybersmart.gov.au/Teens.aspx

There are also links to 'choose your own adventure' videos on YouTube:
http://www.theline.gov.au/follow/4