I am currently 14 years old. I started my programming days back in windows 3.11 land. For Christmas I got a crappy old laptop that had a broken screen, so I had to hook up a CRT fishbowl screen (why are you wincing?). From there I found a DOS 6 manual and started screwing around with colour boot menus (AUTOEXEC.BAT FTW!).
From there I learnt the ins and outs of windows by 'fiddling' (In windows 3.11 I completely screwed the hard-drive during a disk compression error).
I only just discovered Linux in the form of an ubuntu tutorial in the Aussie magazine Atomic MPC. This year I started IT and got my first real taste of programming with VB Express, but I had a teacher to aid with that.
I'd suggest buying him a 'Programming for Dummies', 'The Complete idiots Guide to Programming' book or something like that to get him started.
The original ubuntu tutorial is not on the Atomic website, but there is a new one, Linux for windows users. Look it up at www.atomicmpc.com.au