Those outside the bicycling community have probably never heard of him, but Sheldon was one of the good guys. He had (has) a fantastic website with oceans of technical information that cannot be found elsewhere. Quite the character.
I communicated with him in the fall when I was building my single speed bike. He was helpful and self effacing. Sad to hear of his passing. If you take a look around his site, you can tell he loved life and loved his family.
God Speed.
http://www.sheldonbrown.com/