First, what is IRC? It’s basically internet chat rooms. A lot of people probably want to yell at me for that simplified explanation, but that's pretty much what it is. There are lots of different rooms based on lots of different topics. You pick a nickname when you join and then you can join different rooms and chat with people. You can also run your IRC configuration on a server which enables you to stay connected when you close your computer and read back when you are back at your computer with some time.
I personally don’t hang out in too many rooms. I’ve found that it’s also helpful to ask someone “in the know” about these channels. Some channels are super friendly. Others are really good about answering questions on specific topics or functionality (like the Pry channel). More are based around open-source projects (like the Spree channel). Finally, some channels are really unfriendly and people are kinda mean. I avoid those channels for obvious reasons.
Next, there are a few different ways to access the IRC servers. Some are more complicated and some are less. I, personally, use irssi, which accesses IRC via the terminal but can be a little complex to set up. I enjoy using irssi, however when people post gifs, they don’t show up inline, which means you have to click on them to see them, which can be a little annoying sometimes. Other options include Textual, Limechat, and Colloquy. There are various free trials and free versions, but a few are paid for. Here are some set up options from Chris and Sean . For irssi in particular, in addition to Sean's set up there are lots of additional scripts you can run to make lots of stuff happen including styling of the window, colors, replies, links, and much much more. Here's a pretty good guide to using irssi and here's an additional article abut IRC in general written by Spree Commerce. The Spree article gives even more options for accessing IRC.
Now for some basic functionality tips and tricks. When you want to join a channel, you just type
/joinfollowed by a space and the channel name. To direct a message to a specific person, just start the message with their nick name. You can even start by typing the beginning of the nickname and pressing tab to complete the name. To put yourself into a reply (like *allie_p goes to make coffee) just type
/mein front of what you want to post in the chat. Finally, to send a message to someone just type
/msgfollowed by a space and the nickname of the person you to message followed by the message you want to send. The message to that person will show up in a new window. With IRSSI, you can have multiple windows open (which means be in multiple rooms or conversations) and you can switch back and forth between them by pressing CTRL P or
/win 3 (or whatever window you are trying to get to). To scroll up or down in a conversation, you use FN and then up or down arrows.
Final tips and tricks… check out http://textfac.es to learn about the weird faces you may see in the channels (I still don’t really understand half of them) and reacting gifs for great gifs to post in response to things.
If you’ve got more tips and tricks, feel free to add them in the comments!