What you're looking for is the verbatim environment. It's similar to <code>...</code> in HTML and is written like this:

\begin{verbatim}
#!/usr/bin/perl

for (1..10) {
    print "Hello, world\n";
}
\end{verbatim}
[download]

The result would look like this:

#!/usr/bin/perl

for (1..10) {
    print "Hello, world\n";
}
[download]

Also, you may find some of the tutorials here useful if you're in a rush to see if you and LaTeX get along.

— Arien