\documentclass[11pt]{article}
\usepackage{fullpage}
\begin{document}
Your text
\end{document}
Once you enter your text, you'll need to compile the file with latex using a command of the form
pdflatex filename.tex
The above program produces a file with extension .pdf. Alternatively, you can use latex filename.tex to obtain a file with extension .dvi that you will consecutively need to convert to a .ps or .pdf file using a command such as dvips or dvipdf.
A somewhat longer (but interesting!) introduction to LaTeX that I wrote many years ago can be retrieved here in ps or pdf format. A more comprehensive coverage of Latex and its capabilities can be found here. And, of course, any wisdom found on the web is your additional resource.