Translating debconf templates
You can approach debconf translation work in two ways: you can be active and seek out packages to translate and update, or you can be reactive and translate and update packages when someone requests it to be done. Usually, nobody takes a purely active or reactive stance; for example, lately I used to react to calls for translation updates, but when I had some spare time I would go translate a couple of new packages.
When you work actively, the web page whose URL you need to know is http://www.debian.org/intl/l10n/po-debconf/. There you have links to all languages for which there are translations. Click on yours, and you’ll see a page listing the state of every source package’s debconf template translations for your language. First, you see the partially-translated packages, then the fully translated packages, and finally a list of packages which are not translated to your language. For each package in the first two sections you can download the .POT and .PO files; the names of the packages in the last section just link to a big webpage from which you can download every package’s .POT file.
In the top part of the page you have links to other useful pages. An interesting one is the ranking page, which lists all the languages in order of completeness.
For working reactively, you need to subscribe to the debian-i18n mailing list, because when there is a call for updates or for translations it is always sent to that mailing list. Also, if there already is a translation for your language, another email will be sent to the translation group’s mailing list, as well as to the file’s latest translator.
Calls for translations include information on the deadline and the package maintainer’s preferred methods for submitting the translation. There may also be some notes from the package maintainer. Finally, the .POT file is attached to the call for translations sent to debian-i18n, while the old .PO file is attached to the call for translations sent to the group and the latest translator.
Calls for translations can be sent by the package maintainer when the debconf templates have been modified and the translations need to be updated, but they can also be sent by other people for many other reasons. For example, for the last months there’s been a campaign to upload packages for which there were newer translations that hadn’t been uploaded yet, so NMUs for these packages (non-maintainer uploads) were announced, including a call for translations. Also, there was a campaign to review all packages’ debconf templates, make them more consistent, improve their grammar, etc., and a call for translations was issued for every package after the review.