#debian is an IRC channel kindly hosted by OFTC and freenode which you can join for realtime discussion with other Debian users. To join you need an IRC client: apt-get install irssi, or xchat, or talksoup.app, or konversation, or kopete. There is also a large number of other alternatives.
See the IRC page for a list of other Debian-related IRC channels. This is particularly important for people who don't speak English well, or who are using architectures other than i386. See the FAQs page for further FAQs.
The channel's basic rules are outlined below.
Study the issues first
1. Please read the documentation and manual pages. Show that you have tried to do this. It is unhelpful if others need to dig this information for you. The documentation that you can consult include: man pages, the option --help for the commands, GNU info pages info <command>, package documentation in directory /usr/share/doc/<package>.
How to send questions
2a. Just present the problem and try to be as specific as possible. Say what version of Debian you're running, what you're trying to do, what command you typed (if you typed anything), and what the error message said (if there was one). Consult how to ask smart questions. It also helps, if you put your whole question on one line. It's difficult to follow broken sentences across several minutes on a busy IRC channel.
2b. Be polite and patient. Read http://www.oftc.net/oftc/Constitution#Network_Policy, http://www.freenode.net/policy.shtml and http://www.freenode.net/channel_guidelines.shtml. You might want to read the channel stats too, while you're waiting for someone to answer.
2c. Send question to whole channel, not to a particular person. Especially avoid sending private messages to people. Private messages to the bots in the other hand can send you answers immediately both in the form of static factoids and hooks into the Debian package lists. A bot may already have a canned answer for your question, which helps reduce the load for the human helpers.
Avoid spamming the channel e.g. with advocacy of your project.
Avoid asking questions about other distributions or operating systems that are not Debian (Knoppix and Ubuntu are not Debian; they are derived and have their own channels).
Please disable any public "away" or "back" messages or greetings that aren't followed up with a genuine question; if everyone announced every time they get up to go to the bathroom, no conversation would fit in to these distractions. Don't CTCP people without asking permission or perform other actions that may bother members. The channel tends to average well over 600 people, and if everybody descended to such luserish behavior, the channel would quickly become unusable.
How to proceed if there is no answer
3a. If you don't get answer, just sit tight and repeat after 10 minutes. IRC channels are busy, and people may not respond immediately. In unlucky situation there may not be anyone around to be familiar with the problem at at hand, so repeating in succession won't expedite things.
3b. If the problem still isn't solved, come back in 8 or 16 hours. The channels are very international and people attending from around the globe vary from UTC-7 to UTC+7.
3c. If no one can answer your question, try the debian-user mailing list. You can sign up at http://www.debian.org/MailingLists/subscribe, and post your questions to firstname.lastname@example.org . It is open to non-subscribers, but the default is to NOT CC the original poster with replies (i.e., they only go to the list) so, if you don't subscribe, you'll have to set your Mail-Followup-To field to include both you and the mailing list and/or crawl the mailing list archives on http://lists.debian.org/. Since the list is so high-traffic, it's important to ask a smart question. Include all the information you think is relevant, and make sure you tell us what documentation you've looked at, what you've tried and what symptoms led up to the problem. Resist temptation to use subjects containing HELP or URGENT: those posts tend to get ignored without being read (the poster is not a "special case" compared to other posters).
In general, do not ask for private replies. Instead, set your Cc field to point to you and you can get notification when someone answers. If the matter is urgent to your company, there are consultants for hire. When replying, please make a real effort to trim redundant material and avoid top posting for the sake of clarity; instead, use the inline reply style. People read books from top-down, read newspapers top-down, so follow style in replies (someone talks, you reply after it). If people have to work to read the question from the end before they work to solve it, the message gets probably ignored.
In no circumstance, what not to do
4. Telling someone to run 'rm -rf *', or any variation, will get anyone banned. Even if it is said as a joke. It's not funny to make someone new to Debian to delete their data.
I've been banned!
5a. Are you running as root? Please log in as a normal user to access #debian. On Tor? Register with Nickserv and then set a cloak "/msg nickserv set cloak on"
5b. Have you really been banned? If you've been kicked by debhelper for flooding, you can just join again. Please use paste.debian.net in future for transferring large amounts of data. If you have mode +q set, this normally expires after 10 or so minutes.
5c. If you want a ban removing, then you can ask in #debian-ops for a review. This is more likely to be given as time passes, and if you acknowledge any role in the events leading up to the ban. As an indication, very few people are permanently banned from the channel.