The best way to go about this is to create a language-doctype, which is to be placed below the root-element. At the root-element create a "default" language, which is a content-picker that redirects to the default language page. ex.
www.mydomain.com ->
www.mydomain.com/enAnother option is having two text-fields on each page, which have each their language, but this will be far from as flexible as having to seperate structures.
In my implementation I have also created some properties on each language type, like cultureinfo strings for formatting dates to the current language, name of language (which is also used to reference the "select language links on the top) etc.
We run with 10 subsidiary websites, each having 2-4 languages, and this setup runs just fine.