I myself only started using IRC a few weeks back, whenever I needed help. I just figured out things as they were needed, along the way. It would’ve certainly helped if I had an explanatory guide to follow at the time.

I don’t want to write a full feature article on IRC, because it’s already been covered pretty well by others. I suggest reading this tutorial first.

After reading that, here are some quick tips to jumpstart your experience.

• You can stick with Freenode and ignore the other networks for now, as it seems to be the most populated network for most topics.
• If you want to get started right away, the easiest way is to try Freenode webchat. All you need to enter is a nickname and which channel you’d like to join (e.g. #jquery, #rubyonrails, ##math).
• Most channels require authentication before you’re allowed to speak. To do this, type /msg nickserv register <password> <email>. The nick you joined with will be registered to you with the password you specify, and a confirmation will be sent to your email.
• When you join the channel again, type /msg nickserv identify <nick> <password> to use your previously registered nickname.
• One of the most important settings you’ll want to change is to hide join/quit/part messages, to avoid getting your screen getting flooded with useless messages.

Eventually, you’ll want to download a real IRC client. I like to keep it old school with irssi, though I sometimes use Limechat as well. Google around and find something you like :)