WARNING! This website is no longer actively maintained. It is an archive of 2 years work by Doug Belshaw who now blogs at dougbelshaw.com...
By now, if you have followed Parts 1 (the what and the why of podcasting) and 2 (recording your podcast), you should have recorded some spoken audio and saved it in WAV format. Hopefully, as directed in Part 2, you have also collected together any music, sound effects or quotations that you wish to include in your podcast. Today’s part of the guide shows you how to edit the parts of your podcast together and save it as a whole. Part 4 shall deal with putting your podcast on the Internet… 
1. The first thing you should do is open the file containing the spoken audio you want to be heard first in your podcast by going to File/Open (we’ll add jingles, sound effects, etc. later). Once you’ve done this, add all the spoken audio files you want to include in your podcast by going to Project/Import Audio. All your audio files should appear in the main window of Audacity.
2. If you’ve recorded your spoken audio all in one go, you can skip the next two steps. If you have recorded you spoken audio in stages, as was recommended, now is when we put them together. You can copy, cut, paste and delete parts of the audio track just as you would in a text editor by using the Edit menu.
3. The relevant tool is already selected for you by default in the top left-hand corner (it looks like a cursor). Left-click and drag the part you want to copy, cut, paste or delete and then go to the Edit menu to do just that. I recommend consolidating all the spoken audio into one track by cutting from the tracks below the top one and pasting into the top audio file (which should be the first you want to be heard). Paste in order that you want them heard to be heard in your podcast and preview it to get the timings just right. Once you’re happy with it, close all the audio apart from the top file and save it before you go any further! Give it a name like spoken_audio_original.wav 
4. Unless you’ve used a headset with a built-in microphone, you’re likely to have some background noise from your immediate environment as part of you spoken audio. Minimize this by selecting a part of your audio track where nothing but the background noise is present. Go to Effect/Noise Removal and then click on Get Noise Profile. Once you’ve done this, press Preview to hear how it will sound. Adjust the slider to get it just right. (if you make a mistake you can always go to Edit/Undo) Once you’re happy with it, press OK.
5. Now that we’ve removed the background noise, we want to ‘Normalize’ the audio. This means make sure it is a standard level so we don’t have loud parts followed by quiet parts in our podcast. (this could be caused, for example, by inadvertantly moving closer to or further away from the microphone during recording). To normalize the audio, we need to press CTRL-A on the keyboard to select all of the track. Then go to Effect/Normalize and just press OK when the box comes up. When it’s finished processing you should notice a slight change in the peaks and troughs of your recorded audio. Preview it to make sure it sounds alright. Save your audio with a filename such as spoken_audio_noise_removal_normalize.wav and go to File/Close.
6. Now comes the interesting part - adding music and sound effects to your podcast! When you hear my 45-second offering you’ll notice that I include a quotation from School of Rock and a sample from Gorillaz - Feel Good. The latter was obtained by using Audacity to delete the parts of the track I didn’t want, and the former I gleaned from moviewavs.com. Start a new project in Audacity by going to File/New, open your edited, complete spoken word file and then import any sound effects or music you want to include in your podcast.
7. All that’s left now is to position the tracks in such a way as they flow together and create a podcast that is pleasing to the ear, rather than just ‘noise’. Do that by following the quick tips below. It’s worth experimenting, however, to get just that effect that you want! 
a) Position each track where you want it
Click on the Time Shift Tool in the top left-hand corner of Audacity’s main window. You can now drag each track along the timeline to position it just where you want it. (you may find this easier by going to Edit/Snap-To/Snap On)
b) Fade in, fade out and crossfade
Select the piece of audio you want to fade in or out (make sure the Selection Tool is switched on - cursor in top left-hand corner) and go to Effect/Fade In or Effect/Fade Out. Audacity automatically applies the effect for you. If you want to cross fade between two tracks, select the end of one track and the beginning of another and go to Effect/Cross Fade In
There are many other options, including changing the Tempo without affecting the pitch of the audio, adding a bass boost, etc. but for now there’s only really one more thing you need to know to complete the editing of your podcast. If you want to have some type of music in the background whilst introducing the content of your podcast (i.e. whilst your speaking) then you need to reduce the music’s volume. Fortunately, this is easy to do. On the track which include the music, simply move the slider to the left of the track which has a positive and negative symbol on it to the left. Preview all the tracks together and adjust as necessary.
You are now ready to save your podcast. Save your Audacity project file (File/Save Project As…) and export it in WAV format for the moment. In the next part we shall convert the podcast to MP3, upload it to the server and make it available for others to listen to!
If you want to hear my example ‘podcast’ try here: 
Popularity: 6% [?]
At the risk of becoming a member of the “self-congratulations blogging ring - thanks for this excellent series of guides - I’ve learned lots and lots I didn’t know and now I understand RSS feeds much better than I used to!
thanks Doug!
Ed.
Fascinating