One of the co-founders of it is Bill Mollison, I did a youtube search for him and found tons of stuff.
Some of the other videos I watched complemented the wikipedia article nicely.
Temperate Permaculture Strategies - Pt1 http://www.youtube.com/watch?v=BQ0r_yklrDIWhat is permaculture - 8 minutes http://www.youtube.com/watch?v=8X0H7V6dDi8&NR=1
Urban/suburban permaculture, informative - 5 minutes http://www.youtube.com/watch?v=l3_RbgtDnQE
Hope you find permaculture as interesting as I do. These are forest garden systems that you can leave alone for multiple months in a row... fantastic stuff.