Few links for your enjoyment...
GNU/Linux systems and tools
- Debian refcard summarizes the basics for a GNU/Linux Debian beginner.
- Emacs refcard allows to be comfortable with any Emacs keyboard shortcut.
- AUCTeX refcard gives the essential commands of this Emacs add-on in order to edit LaTeX documents.
- Git refcard is a perfect cheatsheet for Git.
LaTeX
- The not so short introduction to LaTeX is a very good introduction to LaTeX for the beginners.
- TikZ for the impatient allows to learn how to draw pictures with LaTeX/TikZ.
- TeXample/TikZ hosts hundreds of TikZ examples.
- TikZ/PGFPlots explains how to make plots with TikZ.
- Matlab2TikZ is a Matlab module which allows exportation of your plots in TikZ/PGFPlots.