LaTeX is a commonly used science, technology, engineering and mathematical (STEM) typesetting program. It is designed to allow writers to focus on content while producing high quality output. Unlike Microsoft Word or Apple Pages, however, it is not a what-you-see is what you get (WYSIWYG) interface, and therefore has a steeper learning curve than some of the more commonly available writing tools. The program is available on a wide variety of platforms, including Windows, Mac OSX, Unix, Linux, and even iOS. For the purposes of getting started, we'll assume you will be using a web-based implementation of LaTeX.
Advantages of LaTeX are a clean, crisp output while allowing the writer to focus on writing and content as opposed to appearance of the final document. Students are highly encouraged to focus on writing the entire document first, then coming back later to tweak the stylization and appearance of their final product.
First invented by Don Knuth in 1970, LaTeX was designed as a tool to help publish a computer programming book. Since then, however, it has been built into a wide number of systems and applications, some free, some commercial, and has been expanded with a wide variety of packages which extend the functionality of the typesetting system.
This guide is intended to provide you a starting reference. Although it looks complex and does involve a bit of a learning curve, once you gain a bit of experience you'll find you can write high quality technical documents very quickly. Please note that there are tons of additional commands and capabilities built into LaTeX that are extremely accessible with just a bit of Google-Fu.