\documentclass[12pt]{article}
\usepackage{url,graphicx,tabularx,array,geometry}
\setlength{\parskip}{1ex} %--skip lines between paragraphs
\setlength{\parindent}{0pt} %--don't indent paragraphs

%-- Commands for header
\renewcommand{\title}[1]{\textbf{#1}\\}
\renewcommand{\line}{\begin{tabularx}{\textwidth}{X>{\raggedleft}X}\hline\\\end{tabularx}\\[-0.5cm]}
\newcommand{\leftright}[2]{\begin{tabularx}{\textwidth}{X>{\raggedleft}X}#1%
& #2\\\end{tabularx}\\[-0.5cm]}

%\linespread{2} %-- Uncomment for Double Space
\begin{document}

\title{Paper Title}
\line
\leftright{\today}{John Doe} %-- left and right positions in the header

\section{Getting Started}

You'll need to label the problems and sections.  One option is to use
$\backslash$section tags (shown above).  I don't like to do this because I
think it wastes too much space... but if you don't have anything to say, it
can save you by making the document look really classy!

\textbf{Another Option}

What I do more often is simply put the ``section'' titles in a
$\backslash$textbf\{\} tag (as shown in this section).  This makes them stand
out, but doesn't take up a lot of extra white space on the page.

\textbf{All the benefits of \LaTeX}

Using \LaTeX for homeworks allows you to do lots of nice things like:
\begin{itemize}
\item Have your work neatly typeset
\item Impress your professors who might recognize the fonts
\item Include equations easily
\item Put math $\in$ the text: $\textrm{money} = \sqrt{\textrm{all evil}}$
\item Not ever have to mess with MS Word
\end{itemize}

Being able to include equations is especially nice.  Say you were doing a
homework the Pythagorean theorem:
\begin{equation}
d = \sqrt{a^2+b^2}.
\end{equation}
It is simple to include it right in the text!  In fact, when doing math
homeworks I often find it simpler to code derivations in \LaTeX.  If I make a
mistake somewhere, I can quickly change all down-line equations with a
find-replace procedure instead of having to re-write or cross out large blocks
of text.

\end{document}