Audacity is the Open Source (free) sound editor that I prefer over either GoldWave or Adobe Audition (formerly Cool Edit). It is available from http://audacity.sourceforge.net.
(note: no www)

Each recording is a “project”. Projects consist of one or more “tracks”. Each time you start recording, you will (normally) create a new track. When you have the result you want, you will “export” the track to an MP3 file.

Don’t be afraid to experiment. It is easy to make a copy of your current track to try things on. If it doesn’t work, delete the new track and make another copy of the original. Plus, you can “undo” anything you do – all the way back to the beginning.

Don’t forget that in order to export music in MP3 format, you’ll need to install the LAME encoder. It is free; you can get it from www.snapfiles.com/download/dllame.html among other places. If you don’t see it in one place, “Google” for “lame encoder”. The first time you try to create an MP3, Audacity will ask you for the location of the encoder you downloaded, and will remember this location for use after that.

Open Audacity, at the top of the screen, Click File | Preferences; the preferences window opens.

If the Audio I/O tab is not visible on the left, use the arrows at the upper right to scroll to it.

Make sure “Play other tracks while recording” is checked.

On the “Quality” tab: Change “Default Sample Format” to16 bit (unless you have a very fast computer and want extremely high fidelity).

On the “File Formats” tab: Click “Find Library” and specify the location you put your lame_enc.dll file into. Then set the Bit Rate to either 96 (good fidelity) or 128 (CD quality).

Click “OK”.

In Windows XP, double-click on the gray speaker icon in the lower right part of your screen (near the clock) and choose “Open volume control”.

Click Options | Properties, then Recording

Choose the correct signal source, make sure it is selected (check-marked), and set the volume slider about halfway up.

Don’t close the volume control. You’ll probably need it again.

In Vista, right-click on the white speaker icon, choose "Recording Devices", sekect the device you will be using (probably line-in for music, mic for voice), and click "Properties". Then choose "Levels" and set the volume most of the way up. You may find (perhaps under an "Advanced" tab or button) an option for "mic boost". Start by checking (enabling) that, and disable it if you find the volume is too high.

In the window near the top right corner of the screen, select the proper audio source (Microphone / Line-In)

Click the RECORD (round) button and put the needle down. (Assuming, of course, that you have already connected your turntable or other sound source to the computer.)

You should see the track appear with the audio signal being drawn on it. If there is no signal, then you probably have the wrong signal source selected, or the music source isn’t properly connected to the computer.

Click on the Windows Volume Control in the taskbar at the bottom of the screen to bring the volume control to the foreground, and adjust the volume slider until the loudest audio signal almost (but not quite) touches the top / bottom of the track window.

Stop the recording and discard (X) the track.

Click Record to start a new track, re-start the music source (put the needle down again), and record!

When the music stops, press the STOP (square) button and zoom to view the full track <Ctrl-F>.

Choose the SELECTION tool. ( the I-beam looking button in the upper left corner of the window – just below the word “File”)

Click & drag to select the beginning of the track, zoom in to view just that <Ctrl-E>

Click and drag to select the “needle pop” and the silence before the music, press <Del> to delete it.

Adjust the volume level as necessary, perform any other desired edits. (Beyond the scope of this tutorial – you’ll just have to have the fun of discovering it for yourself. And it IS fun.)

Connect your microphone, (and earphones, if desired) bring the Windows Volume Control to the foreground. (Click on the button in the taskbar if the WVC is hidden behind the Audacity window.)

Click RECORD and cue to the music, using the volume control slider to adjust the volume.

Stop the recording, discard the voice track with the volume adjustments on it (X), and click RECORD again

Cue to the music. Click STOP when done.

To save the music track alone, or the music and voice as two separate files (i.e. for DanceMaster)

Select the music track by clicking in the control area to the left of the track (The track will turn dark).

Choose File | Export Selection as MP3, and save it in your DanceMaster\Music Files folder. Use the name of the song (Not the name of the dance you are going to cue to that song.). Fill in the ID3 tags info if desired (DanceMaster won’t use it), and click “OK”.

Select the voice track as above, Export it as MP3, naming it the name of the dance from the cue sheet (i.e. "Waltzing with M.E. Cues"), and save it in your DanceMaster\Voice FIles folder.

To save the voice and music files together as a stereo file

Use the Time Shift Tool (the double-headed arrow) to move the voice track into alignment with the music track. (Play and adjust; repeat as necessary)

Select the music track by clicking in the control area to the left of the track (The track will turn dark). Then select the voice track too by holding the shift key as you click on the voice track control area. Both tracks will turn dark.

Click on the track name button for the top track. Choose “Make Stereo Track”.

Choose File | Export Selection as MP3, use the dance name from the cue sheet and save it in the DanceMaster\Music Files folder.

If you get dropouts in your recorded files (especially your voice file):

• Close other programs that are running,

• zoom out to see enough time in the track window for the whole recording (3 to 4 minutes should be enough) before starting, and

• shrink the Audacity window from full-screen to something smaller.