Export your recording as a WAV file. Like Justin42 mentioned, MP3 is a lossy compression format (although it is "good enough" for many purposes now).
However, if you want to create a normal audio CD which will (hopefully) be compatible with your stand-alone player, the final file form must
be WAV. Nero converts MP3's to "WAV" (really PCM audio) on the fly when creating an audio disc.
If your CD-player can play MP3
files, it may be worth creating an MP3 CD. This is really a data CD with MP3 files on it and it can take ca. 7x as much audio as a standard audio CD. Since you're converting lectures
, this may be the way to go- but only
if the CD-player can play MP3's.
As to editing: what ever you're comfortable with- there are a lot of audio editors! Audacity is fine and since you're using it for recording, there's no need to switch. Edit in native mode. I also like Goldwave
(shareware from Newfoundland