\documentclass[11pt]{article}
\usepackage{fullpage} % to remove the annoyingly large default margins
\usepackage{graphicx} % to include graphics

% NOTE: You MUST compile this using pdflatex
\begin{document}

A simple picture inclusion:
\begin{center}
  \includegraphics[width=2in]{points.png}
\end{center}

And here's one with a caption:
\begin{figure}[htbp]
  \centering
  \includegraphics[width=2in]{points.png}  
  \caption{A caption}
\end{figure}

If you want them side by side:
\begin{center}
  \includegraphics[width=2in]{points.png}
  \includegraphics[width=2in]{points.png}
\end{center}

or one after another: 
\begin{center}
  \includegraphics[width=2in]{points.png}\\
  \includegraphics[width=2in]{points.png}
\end{center}


And if I didn't use the \texttt{[width=2in]} specification:
\begin{center}
  \includegraphics{points.png}
\end{center}


\end{document}

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