Hi,
Winston Chang has published a handy reference sheet on frequently used
LaTeX commands. It can be found here:
http://www.stdout.org/~winston/latex/latexsheet.pdf
I've been using it for some time now and happen to like it a lot as a
supplement when working with LyX ... I thought it couldn't hurt to put
it on the list.
-- Christian
P.S.: The sheet has of course nothing at all to do with cheating (how
could it anyway?), that's purely tongue-in-cheek.
- Handy list: The LaTeX2e Cheat Sheet Christian Liesen
-