Definitely check out the Gnomon Workshop Site as a starting point: http://www.thegnomonworkshop.com/
They have tons of great books, DVDs, and tutorials ranging from beginners to advanced. Hope this helps!
Yes that is basically what matte painting is - it did begin in the movie industry where artists would actually paint a scene on large canvases or mattes to be used in the background where the actors would perform. It is mostly used to create environments that either don't exist or would be too costly to film for whatever reason. The first example that comes to mind is the Star Wars movies where all of these planets and sci-fi scenes were brought to life.
Most matte paintings these days use a combination of photos mixed with digital painting to create these beautiful scenes. Gnomon Workshop does have some great training materials, and this can be a very lucrative field if you happen to be skilled at digital painting. Aside from movies you will often see matte paintings in video games, mostly concept art, but it helps give the animators and 3D guys a foundation to build off of.
Thanks Eric for pointing me to the Gnomon Workshop, I was able to get my hands on a dvd set by Dylan Cole that I've found inspiring.
Richard Rickitt | Special Effects - The History and Technique, Chapter 5 is best for matte painting fellows