Hey there,
Not so long ago i leeched such a book off 'utorrent'.
Download utorrent if you dont have it already and search for 'water4gas' and it will come up.
Still havent gotten round to building mine yet, but ive seen some powerfull videos on youtube of guys powering a blowtorch with hydrogen which can burn a hole straight through a bottle whilst remaining cold to the touch of the human body. That can be found here :
http://www.youtube.com/watch?v=07tn7e8g0YI