DocBook Demystification Howto
http://en.tldp.org/HOWTO/DocBook-Demystification-HOWTO/

Raymond, Eric S.
tldp.org

Abstract:

This howto attempts to clear the fog and mystery surrounding the DocBook markup system and the tools that go with it. It is aimed at authors of technical documentation for open-source projects hosted on Linux, but should be useful for people composing other kinds on other Unixes as well.