John Picacio started out with a degree in architecture, moved into comics, then comics covers and then to science fiction book covers. He has illustrated books by Michael Moorcock, Neil Gaiman, Robert Silverberg, Lucius Shepard and many more. He has received the Chesley Award, the World Fantasy Award and was a finalist for a Hugo. His work has also been featured in Renderosity: Digital Art for the 21st Century and several of the Spectrum collections.
He works in a combination of graphite, acrylic and oil, sometimes supplemented with the collage-like use of photographs and digital manipulation. His images often contain areas of abstract texture intermixed with figurative elements and held together with large patterns of vibrant color.
Here is an interview from the SF Site.