\documentclass{article}
\title{Title of Document}
\author{Name of Author}
\usepackage{sagetex}
\usepackage{graphicx}
\begin{document}
\maketitle
You can make it so Sage code gets automatically run:
$$
\int \sin(x)\cos(x) = \sage{integrate(sin(x)*cos(x),x)}.
$$
Also, here is a plot:
\begin{sagesilent}
var('x')
f = cos(x)*sin(x)
pltf = plot(f,(x,-10,10))
\end{sagesilent}
\begin{center}
\sageplot[scale=.3]{pltf}
\end{center}
And here is an image:
\begin{center}
\includegraphics[width=.5\textwidth]{screen}
\end{center}
\end{document}