Question about multi-lingual website
 

Hi,

I would like to create a website that can switch between English, Spanish and Portuguese versions. I know this is 'doable' but I really haven't got it straight in my head how the whole site gets translated. IOW how do I make it so that not just titles and post content is in the selected language but also all of the Wordpress specific stuff or menu items or whathaveyou. I have read references to .mo and .po files but I don't quite get how they are used, especially for a multi-lingual site.

Some guidance would be most appreciated!

Sharon