How to Encode uncompressed audio with Audacity and LAME
MP3 provides great quality compression for about a 10th the file size of uncompressed audio. And most people can't hear the difference between the MP3 and uncompressed audio. Any computer or portable player can play an MP3 file, so it's a universal file format that makes it perfect for podcasting.
With the LAME MP3 encoder you can export your audio project as an MP3 right from Audacity. This tutorial will walk you through the process.