ARRL has a huge number of resources available for this purpose. Prospective Hams can start with the Welcome to Amateur Radio page at http://www.remote.arrl.org/hamradio.html
, and then explore the site from there.
For printed materials, the ARRL catalog has quite an array of different publications. Those on the Help for Beginners page (http://www.arrl.org/catalog/index.php3?category=Help+for+Beginners
) can be useful at describing what Hams can do, and there are some youth-targeted novels about Amateur Radio in their History/Adventure section (http://www.arrl.org/catalog/index.php3?category=History%2FAdventure
). None of these printed materials are free, but they're not free for ARRL (or others) to produce, either.
There's so much involved in Amateur Radio that a relatively small pamphlet wouldn't go very far. The Welcome to Amateur Radio web page mentioned above probably comes the closest, but it doesn't even begin to scratch the surface.
I certainly appreciate your desire to share your enthusiasm for Amateur Radio with your friends. I have the same desire. I'm kind of a low-key guy anyway, so I just talk to folks about what I'm doing as a Ham so they're exposed to it, and if something interests them, they'll pursue it with me. If not, I'm not trying to twist their arms to do something they're not really interested in anyway.
Boyd / N5CTI