Recording multiple tracks, a few basics:
When recording multiple tracks that you want to be synced (lined up) correctly, it is useful to set a click track. A click track is just that: a track which is like an electronic metronome, making a "click" noice to the beat you set for it. To set a click track, go to the "Generate" menu and select "Click Track." From here you can set the tempo, the number of beats per measure, and the number of measures you wish the click track to continue for. Then, when recording, put on the headphones and you will hear the click track plaing while you record. See the end of this article for how to remove the click track from your final recording.
The "Effects" menu has a variety of effects that change the audio waveform (recording) in certain ways. They all can be applied to whole tracks or selected portions of a track. Some of the more useful ones to use in Audacity are:
Amplify--use this to either increase or decrease the amplitude of a selection. It is important to remember that this effect will make the volume of all the sounds within the selection louder. Increase your voice and you will also increase the background hiss. Thus, it is important to get a good recording to begin with.
Echo--you can decide how soon the echo follows the original (delay) and at what percent of the original volume it echoes (decay).
Fade In / Fade Out--these are preset in and out fades wich slowly increase (fade in) or decrease (fade out) the volume of a selection. Importatn: if you apply fades to a whole track, itw ill apply the fade to reach the maximum level of volume within the track only at the very end. Generally, you will only want to select either the beginning or end of a track when applying fades.
Mixing--each track will have its own volume and panning controls. the volume is marked with "+" and "-" signs; the pan is marked "L" and "R." These controls are best adjusted after any other effects have been added to the track. Then you can balalnce the levels of all the tracks, adjust where they sit in the soundfield, and get the levels just right for mixing all the tracks together.
IMPORTANT!!! When you export as an mp3, all the tracks on the screen will be mixed together. Before you export, close out any track boxes you don't want: bad cuts, mistakes, and the click track. Otherwise they will be recorded as part of the mp3.