How can I read man pages in my mother tongue?
I'd also like to contribute some translations.
Where should I go?
Is there a community supported by Canonical?
First part of question already answered. This will answer second part of question.
Look at this page and locate you language and open the page for your language team from the link.
If your language is not in the list refer https://wiki.ubuntu.com/Translations/KnowledgeBase/StartingTeam on how to start one team
These are translated by community of translation volunteers.