I welcome suggestions and corrections to dead links. I refer to these lists occasionally, but the web changes frequently.
Omniglot Song list - Lyrics, translations, & CD suggestions
Dennis Doyle's List - Lyrics & translations
The Irish Page - Midis of the songs
The Irish Page - Lyrics, translations, and a few recordings
Celtic Art Center - Lyrics, phonetics & translations
TG4 Sean Nos singers - Listed by singer, each singer has four songs - lyrics & audio