Here’s how to set up a Freenode IRC account in Pidgin:

1. Open Pidgin; click Accounts -> Add/Edit.
2. Click the Add button.
3. Change the protocol to IRC and enter
   irc.freenode.net as the server.
4. If you have a Screen name (called a “nick” or “nickname” in IRC
   parlance), type it (e.g. MrOpenSource) in the Screen
name field. If you don’t own one yet, make one up.
5. Click on the Advanced tab, and fill in the Real
name field.

Now, register your nickname. This helps people recognize you, protects your
identity, and allows you to send private messages.

1. Click on Buddies -> New Instant Message.
2. Fill in NickServ for Name.
3. Change Account to the Freenode account you just created,
   and click Ok. Now you can “talk” with the
   NickServ robot.
4. The first message you send should be register PASSWORD
   (where PASSWORD is one of your choosing).
5. Next, set an email address. This will give you a way to reset your
   password later should there be a need. Send set hide email on
   to NickServ.
6. Next message should be set email ADDRESS (where
   ADDRESS is your email address)

Then, join #mifos. :)

One problem sometimes occurs when you have connection problems. You may be disconnected from the internet and the IRC server may not realize you’ve dropped off. When you reconnect, you may see what appears to be two of your username in the channel with slightly different names. Like: USERNAME and USERNAME_. Send help release to NickServ, and NickServ will tell you how to release the original, correct nickname.

Further instructions can be found here or by saying help to NickServ. Commands like /msg NickServ help do work in Pidgin.

This guide was heavily inspired by the following article on freesoftwaremagazine.com.

One more final tip: enable the “Join/Part Hiding” plugin to supress the many “so-and-so joined the room, so-and-so left” messages that will likely show up in the channel.