Hi Min Zhang,
I also started to help in the translation to Brazilian Portuguese, and recently advised me to translate everything, even without understanding the context, I think it's the fastest way.
Then I surfed the site and checked some weird things in translation, so I made some adjustments in the .po file, I will climb it through the bazaar.
The file .Po django_language as I understand it translates some areas related to name things, the content is translated mostly manually by the site's editor and doesn't have po file for him.
You have to see the instructions for how to collaborate through the wiki, I'm following the instructions there, although at first I asked to go up the file for me, opening a bug in Launchpad.
I'm still a beginner and I can say that the wiki is very important.
You also need to register on the Launchpad system, and then open a bug there with your .po file attached.
The Bazaar is required to climb the .po file in the official repository, I will do it soon to new version of the file that I'm translating.
The Maren, Sylvain and other administrators are responsible for permissions, and this can take a while. The permission to edit it took to arrive, because the editor may impact throughout the system, and the site can even be cut off if there is a problem, that's what I was told, so that permission takes a little longer. When I got the permission to edit, I saw that really have to be very careful.
I'm still translating the content and in a few weeks I will publish. I am also learning the correct procedures to contribute in the best way.
I used the instructions from this link at the beginning when I was translating the .po file:
And when you have permission to edit the site, this link is very useful:
Regards,
Roberto Silva
twitter: @Tipigao