\documentclass{article}
\usepackage{a4}

\title{A simple LaTeX example}
\author{Andrew C.R.\ Martin}
\date{28th November, 1996}

\begin{document}
\maketitle

\begin{abstract}
This is the abstract. It will be set in a smaller font and centered.
\end{abstract}

\section{Introduction}
This is the beginning of the first section which I have called the
Introduction.

\subsection{How to so a subsection}
This is a subsection of the Introduction which I have called
\emph{How to so a subsection}. Notice that that last bit was
emphasised in italics. I could also have made it {\bfseries bold}.
If you want you can do sub-subsections as well.

\section{Tables}
This is how you do tables. First of all you define a table
`environment' (note the opening inverted comma!). This is
known as a `float' since it can float around the page to find
the best place to fit. There are floats for both tables and
figures. Within the table environment, you create a 
tabular environment (which you probably want to be centered)
in which you enter your data:

That created Table~\ref{tab:example}. There were three columns
(defined by the ``lll'' part --- note how I got double inverted
commas there and also how I made the long dash). The hline
commands were used to create horizontal lines. The columns
were separated by ampersand characters and each line was ended
with a double backslash. I also have the table a caption and
put a label inside that caption. This lets me refer to that
table anywhere in the text without having to remember the
table number. If I add an extra table before this one, the
number will be corrected automatically.

\section{Running LaTeX}
This is how you convert this into a PostScript file:
\begin{enumerate}
\item Call the file sample.tex
\item latex sample
\item latex sample (\emph{Do it again to sort out references from
one place to another in the text})
\item dvips -o sample.ps sample
\end{enumerate}

You now have a PostScript file you can print! If you are using
the BibTeX package for looking after your bibliography, you
run {\tt bibtex sample} (note that was in typewriter font)
after the first run of LaTeX and you need to run LaTeX an
extra time before {\tt dvips}.

\begin{table}
\begin{center}
\begin{tabular}{lll} \hline
Column1 & Column2 & Column3 \\ \hline
data    & junk    & rubbish \\
arghh   & splat   & bump    \\ \hline
\end{tabular}
\end{center}
\caption{\label{tab:example}This is my first table}
\end{table}

\section{Figures}
For figures, you create a figure environment just like the
table environment. To import a PostScript (EPSF) figure, you must
\begin{verbatim}
\usepackage{epsfig}
\end{verbatim}
up at the top with the other usepackage commands (note how
I used the verbatim environment so LaTeX wouldn't try to
interpret the use package as a command) and then use the
psfig command to import a postscript file.

Since I don't have a PostScipt example for you, I've
shown an example within a verbatim environment so LaTeX
won't actually run this, but you can run it by removing
the verbatim environment:

\begin{verbatim}
\begin{figure}
\centerline{\psfig{file=example.ps,width=10cm}}
\caption{\label{fig:example} This is my example figure}
\end{figure}
\end{verbatim}

You an import other types of images in a similar way.

\vspace{1in}
{\LARGE Have fun!!!}

\end{document}