There are several options, but I’ll highlight two:
Export as WAV file. This is the best way to save your recording if you want to edit it later. WAV files are uncompressed audio and contain exactly what you recorded. They are also very big, about 10 megabytes for 1 minute of stereo sound. If you want to burn your recordings to a CD-R, WAV files are the way to go.
Export as MP3 file. This is the best way for saving recordings that are you want to share on the internet. MP3 files are compressed audio, which means they are a lot smaller than WAV files, but their quality is also slightly worse.
To export a recording as an MP3 file from Audacity, you need to install an MP3 encoder first.
You can also use a separate program to create MP3 files. I personally use WinLame (free).
The WAV and MP3 file formats have various possible quality settings. The trade-off is between sound fidelity and file size: the lower the quality, the smaller the file. Obviously, you want to record and save in the best quality possible.
Use these guidelines:
WAV files: 44100 Hz, 16-bit, stereo. You don’t have to worry about this when you use Audacity, but in other recording software you may need to configure this by hand. If you have a soundcard that can record at a higher resolution (e.g. 96 kHz 24-bits), then by all means use that. You can configure the sound quality in the Audacity Preferences screen.
MP3 files: Encode at 128 kbps or higher. Personally, I use 192 kbps with “constant bitrate” (CBR) at 44100 Hz. Some MP3 encoders use “variable bitrate” (VBR) by default, but still not all music players handle that well (especially not players that stream audio over the internet).
In the following article I explain how you can share your MP3 files on the internet.
Read more articles on Piano Clues: