You will find in bug #526087 instructions about the landing page to be
localized for the Thundebird 3 release planned this quarter.
The file is on the SVN repository in your locale folder, preferably commit
directly to SVN and once done, inform in this bug.
Alternatively, you can attach the files to this bug (either individually or as
a zip archive).
If you attach individual .html files, please attach them with the plain/text
News and instructions affecting all locales will be posted and updated if
necessary in the master bug (bug #523583)
Note that this is a very short translation but this is a very visible page (the home page) !
There is one block of text with a link to your local Thunderbird community site
indicated as <a href="PUTLINKTOCOMMUNITYSITEHERE">.
Done in r55046