A bunch of lists have been created, visit http://lists.debconf.org/ for a list of them. At least the Announce List is a MUST-READ for anyone. (http://lists.debconf.org/mailman/listinfo/debconf-announce).
List archives are at http://lists.debconf.org/lurker/splash/index.en.html.
IRC Primary Channel
The organisors use the #debconf-team channel on irc.debian.org for regular meetings and other more ad-hoc communication.
IRC Backup Channel
The backup channel is #debconf-team on irc.oftc.net.
IRC Local Channel
The local team use the #debconf-localteam channel on irc.debian.org for meetings in spanish.
All files and materials needed by the organisation are stored in a Subversion repository. You can ask Andreas, Gunnar or Ganneff to give you access to it when needed.
The main DebConf6 website is at http://www.debconf.org/