Refurbishing PCs For Charity?

Used PC Guy asks: "I'm trying to run a program to recycle PCs for charity to give to underprivileged kids. Trouble is, these kids have never seen a PC. What should I teach the kids if they're about 14-21? Should I teach Windows, Linux or both? What hardware should I be requesting, and what's the best way to test the influx of hardware that's coming in quickly, efficiently and reliably to make sure won't need servicing within another 6 months?"