First off, read the text, don't just look at the pictures!!
There is no need to do this setup until your DJ application is accepted.
This page has setup instructions for Winamp+Shoutcast DSP on Windows. If you use mac OS or linux, there's still hope.
For iPhone & iPad, try Papaya. For Mac you need nicecast, which is not free.

Mac Nicecast setup This is only for nicecast. Skip if not a mac user.
Watch this video, which is not for ErrorFM but pretty complete. I'll list the changes versus the video:

Add Server page: Name = ErrorFM  Address = errorfm.com  Port = 8000  (test server)
Password: ask a chat operator.  The other fields need to be blank.

Quality page:
No change, 128k

Info page: Name = Your show name, long form. URL = http://www.errorfm.com/
Genre, list 2-3 genres you play. Description : Copy your Name field. It's using one of the two.

First, you need Winamp (version 5.x and 2.7x-2.9x). Set up winamp: Use skin Classic or Modern please. Close media library [ML] and open Playlist [PL].
Install the Shoutcast DSP plugin v2.0 for winamp (bottom of page) into Winamp.
(Alternatively, the older v1.9.0 DSP from here, if v2 is giving you a problem)
In winamp, press Ctrl-P (Prefs), then go to plugins/DSP to start Shoutcast, by selecting the Nullsoft SHOUTcast DSP.

(If it complains about a missing NSCRT.dll, then grab this file from here, and unpack it (put nscrt.dll) into c:\program files\winamp. Newer winamp versions will have this problem with the 1.9.0 plugin.)

Alternative solutions for windows exist, such as SAM Broadcaster. If you have this, its better but harder to set up.

SAM Broadcaster setup This is only for SAM Broadcaster, which is not a free app. Skip if using winamp.
You need to look at the below winamp setup, up to the Push to talk heading. The information is the same, where it goes is different. You need to open the Encoders window, and add an encoder there, of type MP3 Normal, or LAME MP3 (In SAM v3 use MP3 Pro). Server type: Shoutcast v1.
Format: 128kbps CBR, 44100 Hz, stereo, or joint-stereo. Server ip is errorfm.com
For Station Name put your long show title. For further help, come in chat.

Other alternatives to shoutcast: VirtualDJ, Edcast (Pick the Edcast DSP for winamp).

Output tab. enter like in the pic. "Use legacy SHOUTcast v1" is really important.
Port 8000 is our test server. The password is given to you by ErrorFM staff during the setup test.
Description: enter your DJ name plus maybe a short tagline.
Genre: list the main genres you play. This attracts search hits on www.shoutcast.com. Ex: "Rock, Alternative, D&B, Hiphop, 80s". Genre must not be blank.
 

  
  
Note: If you turn off "Use Winamp" you can
set song titles manually.

Note: there are two 128 kbps entries,
choose the stereo one.


Shoutcast Input tab should look something like this.
Also note the meter levels. -1 to -10 dB is good.

Don't close the Shoutcast window! V1.9.0 will hide in the system tray, v2 will disconnect and disable the plugin.

Push to Talk and Mixer settings
If you are using an external mixer, set windows recording mixer correctly, probably Line In, and go to the next section.
If you don't want to use the mic, set Input Device = winamp, and go to the next section.
But you do? Good. Here's how to hopefully get Push to Talk to work. Be aware that it doesn't work on all soundcards.
Also, these pictures are for Windows XP. For windows 7 and Vista, see box below.

Start the windows mixer by clicking Open mixer on the Input tab (Input Device must be Soundcard). This opens 2 mixer control windows, one for Play (a.k.a volume control) and one for Record, usually behind it. Find the Recording control. It sometimes has other names, such as Capture.  
Go to menu Options / Properties. Look for Stereo Mix. It can also be called "Stereo Out", "Mixed Output", "What U hear", "Record master", "wave out mix", "mixer" or "Sum" instead. Turn it on.
It may be missing on some PC's, especially Dell.


Then select it as the recording source. The level slider on it acts as master volume for the stream.

For Windows 7 and Vista In Control panel / Sound / Recording, you need to set Wave out mix or similar as "Default device".
See here how to do this.

In Play control (the other mixer window, a.k.a volume control), make sure Mic isn't muted.
Most people will need to enable "+20 microphone boost" in advanced mixer settings.
If you use speakers, and they're not turned down, you will get mic feedback (howling) when you press Talk. Test this. Best solution is to use headphones, or a headset with mic.
To avoild puff noises when talking, keep the mic to the side of your mouth.

Voice chat programs like Skype, Teamspeak, AIM/MSN voice chat and some games will change the selection to Microphone. If you use anything like this, please check Recording mixer before every show.
Warning: any PC sounds will be transmitted when input device is set to soundcard. So beware of AIM, MSN etc, and Windows sounds, or turn these sounds off.

Test the mic and mp3 switching by pressing Talk. You need a listener for this. If you can't get it to work, or can't avoid the mic feedback, use Plan B, or get SAM Broadcaster.
Plan B: Set recording control selection to microphone. Switch shoutcast Input Device between Winamp (music) and Soundcard for mic, for every time you talk. You don't need to press the Talk button. Adjust mic level in Recording control / microphone.

Sound levels
Watch your sound levels with the "Input Levels" meters. They should stay between -1 dB and -10 dB. They should never hit 0 dB. 0 dB means too loud and it will distort the sound. You will not hear this on your end. Also watch the meters when talking, for a good mic level. You can always trust the level on the meters.
To adjust the levels (when not using Plan B): The selected slider in Recording control acts as master volume.
Fine tune using shoutcast: input tab: Music Level and Mic level. BG Music Level is for when the Talk button is pressed. Do not mess with the levels in Play control (a.k.a volume control mixer). Shoutcast is designed to change these for you.

Troubleshooting - common problems
Mic works, but its too low even on max level: In play mixer (a.k.a volume control), enable Advanced in the menus. Then click Advanced button under Mic. Enable "+20 microphone boost" Mic is still too low, even with "+20 boost" on: Raise level on Stereo mix in Recording mixer. Now music is too loud, so lower it using Music level, or winamp's volume control. Mic is on, always, no matter what i do. Music isn't getting through: Yank that webcam with built-in mic out. Some USB mics are like this also. If you want to use this mic, go with Plan B Mic isn't working: Turn off mute in play mixer. Check if there's an on/off switch on the cable. Check where its plugged into the PC, sometimes theres two mic ports. Check shoutcast input tab: Mic input. I can't connect: You can't connect while another DJ is on. Or the password / address / port is wrong.

To start transmission
Load the kick webpage (which is given to you by staff) in case you need it.
If the previous DJ is live, use IRC chat to agree on when to start. Even in this case you may need to kick the auto-DJ off. (It tries to connect every 10 seconds.)
Go to the output tab, select Output 1 and push Connect.
Transmission does not end with the last mp3, you must click Disconnect.

Tell any following DJ to start, or just leave it for auto-DJ to take over.

Test for skipping with a listener. Skipping and rebuffering means you can't transmit fast enough. You will not notice this on your end. If it skips, check for any other outgoing internet traffic, such as file sharing programs or webcam software. The stream requires about 100 kbit/s reliable outgoing (upstream) speed. Measure your speed here (stop all traffic first).

IRC Chat
The current DJ must be in chat when DJ'ing, and check it for listener feedback. Some listeners will be rude. Just ignore them if you can, or have a channel op remove them from channel.
Type !efm to get current stream info in channel.
Type !sched to get a compressed schedule for the next few hours.
Type !listeners to get a list of who in chat is listening.

Useful DJ tips