Teaching Beginners

[JLK]

I'm a student at RCM and have been approached by my mum's friend and his son who would like me to teach them the piano.  I'd love to teach them but haven't really taught anyone before and therefore not very experienced in this area!  I just need some advise on what music to teach and basically how to go about teaching both the father and a little boy of 6?

Thank you!!