you can find the 2003 Science Channel FIRST documentary here
http://www.team696.org/resources.html
it is a 500 mb download
I recomend setting up shop in lunches and at freshman course fairs. Use your teams propaganda there. Show people the bot. Tell them they will be able to drive the bot if they come to a meeting on such and such a day. Try to get kids to show its not just for nerds, and there are many things to do with FIRST. Then, on that meeting day, show them that video or show them anything else. You could show videos from matches from last year. If you dont have any you can go to
http://www.team195.com/media.html and go to the video gallery, some of my teams vids are there..
But what i would say is the best thing to do is try to emphasise that FIRST is for everyone, and it just as fun as a sport. Tell them that builiding the robot only takes up 6 weeks a year. Lots of kids in high school think that FIRST is only for geeks and nerds, and have no reason to join. Give them a reason.