I\'ve been a UNIX sysadmin for a long time, and aside from automating tasks with shell scripting, some light PHP work, and a few simple C programs, I\'ve never done much in the
Well, a good place to start would be the executing lisp section of the info pages.
In general, when you work with an interpreted language in Emacs, you edit the source files, and interact with an inferior process (a new process spawned by Emacs, in this case a lisp process). You can evaluate an sexp (balanced expression), region, or the entire buffer with simple keystrokes. Those commands send the code to the lisp process and evaluate it.
This usage model works for shells, Tcl, lisp, anything with an interpreter...
The wiki has a lot of good information.