https://lists.debian.org/debian-edu - support mailing list
#debian-edu on irc.debian.org - IRC channel, mostly development related; do not expect real time support even though it frequently happens.
https://lists.debian.org/debian-edu-german - support mailing list
#skolelinux.de on irc.debian.org - IRC channel to support German users
https://lists.debian.org/debian-edu-french - support mailing list
Lists of companies providing professional support are available from https://wiki.debian.org/DebianEdu/Help/ProfessionalHelp.