I am almost done with tranlsating everything into Italian.

-copy/paste the "en" folder into language and rename it "es" then change evrything in the "language/es" folder. Change the language configuration to "es" in the config.php file.
-change all your .tpl files in the Templates folder
-change files in the templates/emails
-also, if you want, there are some customizable labels (like email subjects and so on) in a couple of table in the database...

I still have to uess how to change the "Not Yet Rated" label and the "hours ago" labels, but I think that these are embedded into the code...