Scripting
An exciting
and comprehensive book is The Art of Unix
Programming by Eric Steven Raymond, Addison-Wesley 2003. It's entire contents is available here on the
web.
It explains the design philosophy
behind Unix (and GNU/Linux) and why text is important
as a communication mechanism between programs.
It explains what you need from the
operating system in order to carry out scripting - e.g. a CLI (command line
interface).
It also reviews various modern
languages - C, Java, Python, etc