Linux Journal: Frank Mittelbach and Michel Goossens' "LaTeX Companion" (with Johannes Braams, David Carlisle and Chris Rowley) 2nd ed. (Addison-Wesley Professional)
Frank Mittelbach and Michel Goossens' "LaTeX Companion" (with Johannes Braams, David Carlisle and Chris Rowley) 2nd ed. (Addison-Wesley Professional)
Possible Duplicate: How to look up a symbol? Escape character in LaTeX In the itemize environment, how do I use the ampersand symbol & without LaTeX trying to use it as a command?
How do I use '&' literally in LaTeX? - LaTeX Stack Exchange
How does one insert a "" (backslash) into the text of a LaTeX document? And how does one insert a "~" (tilde)? (If you insert ~, it will give you a tilde as an accent over the following letter.) I
How does one insert a backslash or a tilde (~) into LaTeX?
Sometimes the symbol := is used to denote a definition. For example, X:=Y+Z means that X is defined to be Y+Z. When using LaTeX, can I just use $:=$, or do I need to do something special?
How to type these special letters from European languages in latex? ä, é, and L'?
LaTeX still supports it for one reason or another, but the "proper" one to use, as defined in the specifications, is [ ... ]. All this just means that they are not promising that $$ will always work. So it is technically possible (though unlikely in the near future), that compatibility with $$ is removed from LaTeX and lots of your documents ...
Why is \ [ ... ] preferable to - TeX - LaTeX Stack Exchange