If you mean material about Jack, there are several fairly ambitious fan sites, starting with Remy Wetzels' ww.jackvance.com and Mike Berro's www.jackvance.org. Nick Gevers has an appreciation essay at

www.infinityplus.co.uk/no...rofile.htm

with a link to a famous (but perhaps not entirely representative) story, "Green Magic":

www.infinityplus.co.uk/stories/green.htm

If it's JV fiction you want to sample, I'd say just go to a bookstore and pick up a title or two. It's hard to tell what's in print at any given moment, but both US and UK Amazon sites show quite a few titles, including both SF and fantasy. If the price of a new paperback seems too high, just about any fair-size used book outfit should have a decent sample of Jack's back list.