The lyrics category at Yahoo is a good place to look for additional lyrics sites. Nearly 2000 hymns and gospel songs are listed on this site. You'll find lyrics, scores, MIDI files, and brief composer biographies. The database is browsable by song title, topic, tune name or meter, and composer. A searchable database of folk and traditional song lyrics.
Some songs have sound files also.
This site contains lyrics to blues songs, arranged by artist, title and topic. Additionally, there are guitar tablature and chords, a glossary of blues language, and links to information on blues history. A collection of over 300 Irish songs, browsable by title or searchable by keyword. Over 11,000 titles are listed, but not all of them have the lyrics posted. The collection is browsable by year, artist, and title.