Have a look at the Early Music FAQ. I must have bumped into this site in the past but only now have I taken note of how informative it is. It is not religious and seems to attempt a weighting in the direction of secular music, but it is still very enjoyable and useful. It answers basic questions (What are the main pieces composed during the medieval & Renaissance eras?), important specifics (What is Musica Ficta?), and more far-flung questions(How did they make Farinelli's voice?). It includes the complete text for all of Machaut's music (just what you were looking for on this lovely Saturday morning).