LaTeX

Are you tired of overly-smart word processors, too? In september 2001 I was introduced to LaTeX by a well-meaning friend and I personally can never go back to MS Word or Star Office again. It's just so practical, stable, controllable, configurable, neat, sexy nerdy - yes, anytning you would want! (Do I sound enthusiastic?)

First, you need the tools. MiKTeX provides an implementation of TeX that is ready for download for just about any operating system. Get it now!
http://www.miktex.org/

A good place to get started is David Wilkins "Getting Started with LaTeX" website. Wilkins is a lecturer from Dublin University who has spent quite some time making this beginner's guide for LaTeX that will get you started right away.
http://www.maths.tcd.ie/%7Edwilkins/LaTeXPrimer/

When you are done with the first introduction, you should read the "Not So Short Introduction To LaTeX2e" by Tomas Oetiker et.al. It can be downloaded in various formats from:
http://people.ee.ethz.ch/~oetiker/lshort/

The research project LaTeX3 Project provides many articles, documentation, bug reports and a most useful FAQ (Frequently Asked Questions). I particularly used the FAQ in the beginning.
http://www.latex-project.org/

Naturally, the complete LaTeX2e reference is nice to have handy. It can be found at multiple sites, one on which is listed below:
http://www.sci.usq.edu.au/staff/robertsa/LaTeX/latex2e.html

For typesetting graphs and diagrams directly in LaTeX I can really recommend XY-pic. Great for state machines and much more.
http://www.ens-lyon.fr/~krisrose/Xy-pic.html

Although there is much material available on the web (use Google to find more) there are also some very useful books around. I have Lamport's "LaTeX - A Document Preparation System" but really also ought to buy "The LaTeX Companion" by Michael Goossens et al.