I'm sure you've checked out wikipedia:
http://en.wikipedia.org/wiki/Pirc_Defence
And this nine minute video:
http://www.youtube.com/watch?v=7z66hiJAqmo
But this you probably haven't seen. Here's a one hour video by Yasser, on the Pirc, that's worth watching:
http://www.chesstape.com/index.php/openings/yasser-seirawan-opening-ideas-in-the-pirc-defense
Could someone tell me all about this opening and some of the main lines