Currently there are local teams in Norway, Germany, the region of Extremadura in Spain, Taiwan and France. "Isolated" contributors and users exist in Greece, the Netherlands, Japan and elsewhere.
The support chapter has explanations and links to localised resources, as contribute and support are two sides of the same coin.
Internationally we are organised into various teams working on different subjects.
Most of the time, the developer mailing list is our main medium for communication, though we have monthly IRC meetings on #debian-edu on irc.debian.org and even, less frequently, real gatherings, where we meet each other in person. New contributors should read our http://wiki.debian.org/DebianEdu/ArchivePolicy.
A good way to learn what is happening in the development of Debian Edu is to subscribe to the commit mailinglist.
Documentation writers and translators
This document needs your help! First and foremost, it is not finished yet: if you read it, you will notice various FIXMEs within the text. If you happen to know (a bit of) what needs to be explained there, please consider sharing your knowledge with us.
The source of the text is a wiki and can be edited with a simple webbrowser. Just go to http://wiki.debian.org/DebianEdu/Documentation/Stretch/ and you can contribute easily. Note: a user account is needed to edit the pages; you need to create a wiki user first.
Another very good way to contribute and to help users is by translating software and documentation. Information on how to translate this document can be found in the translations chapter of this book. Please consider helping the translation effort of this book!