First, you need to understand what it takes to display content in
different languages on a computer. On a web page, this is affected by
a number of things: (1) the web page's encoding, (2) the browser's
language settings and (3) the computer's (the one with the browser)
language settings.
Secondly, you need to determine if your multi-language site will
display only one language at a time, or if two or more languages are
displayed at the same time. If it's the former case, you have lots of
encodings (look up the term) to choose from. If it's the latter, use
Unicode (
http://www.unicode.org).
You've got a lot of research to do.
Good luck.
epp