bruce sterling
 

what book of his should i read first?

If you've read Gibson, you might want to check out their collaboration The Difference Engine. But only if you aren't exclusively looking for cyberpunk because it's actually one of the first steampunk books. It's a great read regardless.

The only other Sterling novel I've read was Heavy Weather which I don't really recommend at all.

I've not read a massive amount of sci-fi, but from what I have I'd say that in some ways I actually prefer Sterling to Gibson, especially his earlier short stories, which seem to me to be a bit more in the 'classic sci-fi' vein. The Crystal Express is a particularly good selection. Schismatrix is probably my favourite of his novels.

this novel and the stories in Crystal Express that compliment it make up a grand space opera, and it has held up to repeated readings since the 80's.

one of my best library sale scores ever was a 1st edition hardcover of Schismatrix for a dollar.

absolutely essential (and 1st generation) cyberpunk

Yes. It's a shame that he never really went further with his whole 'Shaper/Mechanist' concept which I think could have developed into something far more interesting than what Gibson did with his whole virtual reality thing.

From what I can gather, Sterling has had a slightly bigger influence than Gibson among non cyberpunk sci-fi writers, such as Alastair Reynolds.