You can contact the organizers via the following email adresses:

30C3-orga (at) cccv.de
for organisational issues
30C3-content (at) cccv.de
for conference program-related stuff
30C3-tickets (at) cccv.de
for questions concerning the ticket sale and tickets
30C3-press (at) cccv.de
for press and pr issues


There is also an IRC-Channel #30C3 at hackint and freenode. You won't get any official information there, but you can get in contact with a lot people participating the congress. Most of them will be able to answer main questions as well, as there are a lot people involved in running the congress. Be one of them!