Before searching for support from someone else, it's usually good to try to find an answer to your problem yourself. That way you will usually get the answers you need, and even if you don't, the experience of reading the documentation will likely be useful for you in the future.
See the Debian documentation page for a list of documentation available.
Debian is developed through distributed development all around the world. Therefore e-mail is a preferred way to discuss various items. Much of the conversation between Debian developers and users is managed through several mailing lists.
For general Debian support, you can use the Debian user mailing list.
For user support in other languages, please check the mailing lists index for users.
On-line Real Time Help Using IRC
To connect, you need an IRC client. Some of the most popular clients are HexChat, ircII, irssi, epic5 and KVIrc, all of which have been packaged for Debian. Once you have the client installed, you need to tell it to connect to the server. In most clients, you can do that by typing:
Once you are connected, join channel
#debian-user by typing
Note: clients like HexChat often have a different, graphical user interface for joining servers/channels.
There's a number of other IRC networks where you can chat about Debian, too. One of the more prominent ones is the freenode IRC network at chat.freenode.net.