How to Export an Audacity File As an MP3 in 2 Simple Ways
Audacity tutorial: Converting to mp3 or AAC and other formats, example: Matthew Smith - epic orchestral synth music for film and game effects; Buanzo's LAME mp3 library
How to Save MP3's in Audacity With the LAME Encoder - YouTube
Audacity 2.1: Der LAME MP3 Encoder und andere Audiocodecs -