Bruce gives an overview of Agile, starting about three minutes into this video. While many talks on agile get caught up in the details of implementation, this video makes the tenets of agile approachable. I suggest that you watch it, and feel free to share it with your family so that they can understand what you do at work. My kids are a bit too old (Claire, 28 and Peter, 30) to apply this at home, so I’ve got to apply the principles at work.
If you want a deeper view of Scrum, look at the Scrum Guide, available on the web and just recently revised. There are a large number of videos on Scrum on Youtube. One, Explaining Scrum in less than 120 seconds is a great introduction. A more detailed view and history can be found, from Ken Schwaber in 2006, as a Google Tech Talk; the video runs about an hour.