LaTeX Help for Beginners
Here are three sites I have used a lot for $\LaTeX$ codes.
The first link is mostly about creating $\LaTeX$ documents and may not be needed but there is a glossary of commands (codes) that might be helpful.
http://en.wikibooks.org/wiki/LaTeX/Absolute_Beginners
The next two links are "cheat sheets" for codes that I have printed out and keep handy in my binder.
http://www.scribd.com/doc/191838/LaTeX-Help-Sheet
http://sabioacademy.com/default.aspx?lang=en&tab=16&cpage=22
Actually, I just printed the code sheets offered on this site by following the links from the side bar, "help" - "how do I typeset mathematics?" - and then "here" at the bottom of the page. Here is what I just printed - very nice!
Cathy Fulkerson Ajamie