Sorry its taken so long to respond to this post. My intention was to write some documentation of my recommendations which I still have not had a chance to do, but I will do this soon and post again here when I get to that.

The short story is my recommendation is to use 1 site per language not try and do multiple languages in one site. I have never seen a site (on the internet) that effectively supports more than one language in the same site.

In mojoPortal, resources like labels and button text come from the resource file and adapt to the language settings of the browser if resources for the preferred language are available otherwise it falls back to the default as specified in web.config:

<globalization
            culture="auto:en-US"
            uiCulture="auto:en"
            requestEncoding="utf-8"
            responseEncoding="utf-8"
            fileEncoding="iso-8859-15" />

in the example, auto tells it to try and pick resources based on the user's browser language preference, :en-US says en-US is the default to use if the preferred resources cannot be found.

However since the vast majority of text on any page is coming from the db, it all depends on having content authors for the languages you want to support. Since it really doesn't make sense to have pages with both languages I think it is much better to give each language its own fully supported site.
Of course you could just organise different language pages in the menu if you want to.

Hope it helps,

Joe