IRC (Internet Relay Chat) is not covered in the Eric Raymond document, but IRC can also be an excellent way of finding the answers you need. However it does require some practice in asking questions in the right way. Most IRC networks have busy #linux channels and if the answer to your question is contained in the man pages, or in the HOWTOs then expect to be told to go read them. The rule about typing in clear and grammatical English still applies.
Most of what has been said about newsgroups and mailing lists is still relevant for IRC, with a the following additions
Do not use colours, bold, underline or strange (non ASCII) characters. This breaks some older terminals and is just plain ugly to look at. If you arrive in a channel and start spewing colour or bold then expect to be kicked out.
Remember you are not entitled to an answer. If you ask the question in the right way then you will probably get one, but you have no right to get one. The people in Linux IRC channels are all there on their own time, nobody is paying them, especially not you.
Be polite. Treat others as you would like to be treated. If you think people are not being polite to you then don't start calling them names or getting annoyed, become even politer. This makes them look foolish rather than dragging you down to their level.
Don't go slapping anyone with large trouts. Would you believe this has been done before once or twice? And that we it wasn't funny the first time?
Most #linux channels are English channels. Speak English whilst in them. Most of the larger IRC networks also have #linux channel in other languages, for example the French language channel might be called #linuxfr, the Spanish one might be #linuxes or #linuxlatino. If you can't find the right channel then asking in the main #linux channel (preferably in English) should help you find the one you are looking for.
Do not type like a ``1337 H4X0R d00d!!!''. Even if other people are. It looks silly and thereby makes you look silly. At best you will only look like an idiot, at worst you will be derided then kicked out.
Never ever ask anyone to port scan you, or try to ``hack'' you. This is inviolable. There is no way of knowing that you are who you say you are, or that the IP that you are connected from belongs to you. Don't put people in the position where they have to say no to a request like this.
Don't ever port scan anyone, even if they ask you to. You have no way to tell that they are who they say they are or that the IP they are connected from is their own IP. In some jurisdictions port scanning may be illegal and it is certainly against the Terms of Service of most ISPs. Most people log TCP connections, they will notice they are being scanned. Most people will report you to your ISP for this (it is trivial to find out who that is).
Don't /msg anyone unless they ask you to. It diminishes the usefulness of the channel and some people just prefer that you not do it.
Stay on topic. The channel is a ``Linux'' channel, not a ``What Uncle Bob Got Up To Last Weekend'' channel. Even if you see other people being off topic, this does not mean that you should be. They are probably channel regulars and different conventions apply to them.
If you are thinking of mass CTCP pinging the channel or CTCP version or CTCP anything, then think again. It is liable to get you kicked out very quickly.
If you are not familiar with IRC, CTCP stands for Client To Client Protocol. It is a method whereby you can find out things about other peoples' clients. See the documentation for your IRC for more details.
Don't ask about exploits, unless you are looking for a further way to be unceremoniously kicked out.
Don't be in hacker/cracker/phreaker/warezer channels whilst in a #linux channel. For some reason the people in charge of #linux channels seem to hate people who like causing destruction to people's machines or who like to steal software. Can't imagine why.
Apologies if that seems like a lot of DON'Ts, and very few DOs. The DOs were already pretty much covered in the section on newsgroups and mailing lists.
Probably the best thing you can do is to go into a #linux channel, sit there and watch, getting the feel for a half hour before you say anything. This can help you to recognize the correct tone you should be using.
There are excellent FAQs about how to get the most of IRC #linux channels. Most #linux channels have an FAQ and/or set or channel rules. How to find this will usually be in the channel topic (which you can see at any time using the /topic command. Make sure you read the rules if there are any and follow them. One fairly generic set of rules and advice is the ``Undernet #linux FAQ'' which can be found at http://linuxfaq.quartz.net.nz .