Hi LunarNewbie!
I've seen it done a couple ways, for example
yoursite dot org/de/index.html , yoursite dot org/fr/index.html
yoursite dot org/de-index.html, yoursite dot org/fr-index.html (look at the W3C section on translation, they make use of this method)
Use the common abbreviation, not the full name of the language. Also be sure to put the correct lang tag (lang="en" , lang="fr", etc) in the top of each page's code after the doctype. It could be easy to slip up if they are copied from one page to the next. The W3C site explains the lang tag pretty well. Basically it tells the browser which language the document is in. With it in place, a browser can get a grip.
Agreed that the different translated versions should be in different folders. There should be no duplicate content penalties either.
Now about getting found. First, IF you post lots and lots of useful text content, even if it is all in one English version, users WILL find you from all over the world using the various local Googie / search engines. Yes, if they are interested, they will find it!
Next, how do you plan to get the versions translated? Human expert translation is a truly valuable addition to the web.

Automated translations are not worth creating a separate page for. The search engines will not likely find them worth enough added value to be indexed. Users can find these auto-translators on their own. Auto-translations are not really good enough yet, but someday they will get there, we can dream.
For being found, the name and structure of your folders and files is not as important as the page titles, descriptions and first paragraph. Be sure to put your most important search terms / keywords for each page into the title.
Hope this is useful.