Editing your .emacs file

.emacs files are written in the programming language LISP.

setq – “set quoted” – this is the way you normally set a variable globally. the variable name is not evaluated, but the value arguement is unless quote is used
(setq variablename value) or can have multiple values set like (setq variablename1 value1 variablename2 value2)

quote – tells lisp not to evaluate the value of the quoted item
(setq a 17 b (quote a)) is equivalent to (setq a 17 b ‘a) 
value of a: 17, value of b: a, value b would be if quote were not used: 17

nil – means “false” or equvalently in lisp, empty list
t – means “true” (although any value other than nil can be used, t is good programming style)
* note that in emacs lisp nil and t are special symbols that will always evaluate to themselves, so you don’t need to use quote on them to use them as constants