\begin{document}
\lstset{language=TeX}
Here is the code I'm taking about:
\begin{lstlisting}
\documentclass[11pt]{article}
\title{My first \LaTeX Document}
\author{Isabelle HURBAIN}
\begin{document}
\maketitle
%testing out listings.sty for first time
Hello, world!
\end{document}
\end{lstlisting}
\end{document}