Using the .emacs file

Here you will need to know (or copy) a bit of Lisp. Here are some examples.

(global-set-key "\e#" 'quoted-insert) 
(define-key c-mode-map  "\e#" 'quoted-insert)

These both set M-# to perform a quoted insert.

(global-set-key "\C-cg" 'goto-line) 
(define-key ctl-x-map "g"    'goto-line)

Make C-c g and C-x g prompt for a line number to jump to.

The function keys can also be set to do things -

(global-set-key [f1] 'goto-line)  ;; goto line number