post process audio file most people at librivox use audacity (a free program)
some noise cleanup if necessary
edit out stutters, stumbles, re-reads,
intro: 0.5sec to 1sec of silence before intro speech
extro: leave 5 sec silence after end of reading. this gives a nice sample for noise-cleanup.
check for ending "click noise spike" at end of recording when record button shuts off (this applies more for people recording on portable standalone mics).
export as mp3 file