Resources

Saint BenoitHere are some resources for learning Gregorian Chant and the traditional Latin Mass.
http://gregorian.soft.free.fr/gregorian.html

The following site provides recordings and scores for the Ordinaries and Propers for the entire ecclesiastical year! By playing the recordings daily, your group can slowly and deliberately learn the chants of the Church.
http://www.sanctamissa.org/en/music/gregorian-chant/chant-liturgical-year/christus-rex-full-liturgical-year.html

If learning the Gregorian Chant propers is daunting for your group, try learning the ordinaries for the Missa de Angelis and Orbis Factor Masses. Then use the simplified Rossini Propers.
http://www.musicasacra.com/pdf/rossini.pdf

Guide to Square NotesPater Noster Chant Fragment
http://ceciliaschola.org/pdf/squarenotes.pdf

A Gregorian Chant Master Class
http://www.abbeyofreginalaudis.org/video&chant.php?mediaID=2&autoplay=0#top

The Chant Cafe
http://www.chantcafe.com/

This is one of the best hymnals available.
http://www.stmichaelhymnal.com

Getting Acquainted with the Latin Mass

This is an excellent interview of Father James Fryar, FSSP, who explains the traditional Latin Mass.

Part 1

Part 2

Part 3

Part 4