What (if anything) did he do before he wrote?

WG provides us with a brief biography here:
http://www.williamgibsonbooks.com/source/source.asp

When I read it the second time, after I had gotten to "know" WG through his blog, the first paragraph made me cry.

Actually, if Bill's past had been a bit more sordid, like Charles Bukowski, or William Burroughs he'd have gotten a lot more cred, and maybe a Pulitzer.

You're probably right about that, B-jac.

Gibson's lack of a public persona has probably undermined his chances at that kind of thing.

They had to give him the Hugo and the Nebula and the P.K.D. because if those awards skipped over everyone who was shy and reclusive, they wouldn't have anyone left to honor in S/F.