At least four official Klingon works have been translated into German: http://www.qephom.de/e/books.html#german
...and then, of course, there's Quvar, "the Klingon teacher from Germany
There's a fair bit of Klingon info out in Japanese. For example, there's this website: http://www.netlaputa.ne.jp/~qapla/asaga/stkc.html
...as well as Twitter accounts like @theklingonway
A Japanese version of the game Star Trek: Klingon also recently appeared in the Japanese iOS app store, but unfortunately it seems to lack the language lab and many of Marc Okrand's language notes.
The Klingon Dictionary has also been translated into Portuguese, but I don't believe it's still being printed: http://blogdoreco.blogspot.se/2012/02/jornada-nas-estrelas-dicionario-da.html
I also tweet in Swedish a few times a day using the Twitter account @klingonska
; not really to make in-depth information more accessible, but to raise interest. ...and, as Klythe mentions, maHvatlh has founded Klingonska Akademien
, which provides a lot of good information in both English and Swedish.
To make information about Klingon grammar more accessible to speakers of a particular language, one of the best things one can do, by my assessment, is to make sure that language's Wikiepdia page on tlhIngan Hol is up to snuff; because Wikipedia has a very high Google ranking, updating those pages is a good way to make sure people can easily find good information.