Autocompletion in Auctex

["Lorenzo Isella" <lorenzo.isella@gmail.com>]

Dear All,
I have started to use Auctex for editing my latex documents.
It generally works great, the only thing I am missing is some way to
get autocompletion for e.g. referencing and citing.
It would be great if when typing \ref{} or \cite{} I had a pop-up or a
buffer telling me what I could possibly cite/reference.
I did a bit of online research and bumped into:
http://www.informatik.uni-hamburg.de/RZ/software/emacs/auc-tex/auc-tex_3.html

http://people.debian.org/~psg/elisp/   , which led me to:
http://cvs.savannah.gnu.org/viewvc/*checkout*/auctex/auctex/bib-cite.el?revision=5.38

This should get the job done. [Am I correct here? FYI, I am running
Debian Testing on my box and installed emacs and auctex from standard
repositories].
However, I am missing the basics, that is to say: I download and put
somewhere this bib-cite.el file; what should I write in .emacs to let
emacs know where to read it? Can I include it directly in my .emacs
file somehow?
Many thanks

Lorenzo