This is exactly what I'd like to help with. Some of the documentation/software that I have for certain soundcards can't be found online (AFAIK), and it would be great to make it widely available.
I've made some attempts to do this using the forum (the MPU-401, Game Blaster, and IMFC threads), but it would be great if there were an actual web "repository" for such information. Jim Leonard, the MobyGames creator, told me over a year ago that he had planned such a website, though I've not heard anything about it since.
It's on the extended to-do list. My goal was a website -- now probably a mediawiki -- that tried to preserve the history and sound of sound cards, from the birth (Mockingboard?) up to but NOT including the software wavetable era. Hardware wavetable, like daughterboards and the GUS family, would be the last date in the timeline I'd want to cover.
I received a large donation of GUS stuff -- some prototypes, even -- so I'm covered there. The site/wiki/whatever is planned to be a shrine, essentially: Pictures, manuals, audio examples, programming information, trivia, recommended programs that use it well, etc.
I should have time around June/July.