For getting the most out of assisting at the Traditional Latin Mass the purchase of a Roman Missal is recommended. Here are a few links to various publishers: Baronius Press: http://www.baroniuspress.com/category.php?wid=59&cid=2 Angelus Press: http://angeluspress.org/Books/Missals Priestly Fraternity of Saint Peter: http://www.fraternitypublications.com/hand-missals.html For those who like the great liturgical commentaries in the St. Andrew Missal (1952 edition – slight differences from 1962 ed.), you may find it at various locations on the Internet, see Fraternity Publications above. Finally there are also the Father Lasance editions, also pre-1962, that contain pictures of what the priest is doing. See Fraternity Publications. Second hand copies can be found with a bit of searching on the internet. Try Bookfinder.com, or Amazon’s book market.