Concept art is the corner stone of any project, and often (at least to me) is the most interesting part of any project. It often shows the viewer the intent/feel of the project as well as setting forward the overall design/look of the project in question. While any particular studio or company often only employes 2 or 3 concept artist at a time for a single project the pay of is quite nice, the average salary of a concept artist is in the 72,000 range. As far as skills are concerned for a basic concept artist are overall great drawing skills, still life, life, perspective as well as painting. And the ability to take what they create by hand and then turn around and scan it into a computer and improve it even further. Concept art covers the entirety of any project from the setting/scenery to the props and characters.