If you run Windows, the easiest way to get Latex on your computer is probably using proTeXt. This gives you a short clickable pdf document with links to install everything you need.
If you have a Mac, MacTeX should be more or less the same thing.
If you run Linux, the current tex packages for most distros seem to be TeXLive.
This is a sample latex template. It is based on Peter May's REU latex template but with more examples. tex file dvi file pdf file
Here are some useful reference for using Tex and Latex: