An interesting liturgical resource online is the List of Uniform Titles for Liturgical Works of the Latin Rites of the Catholic Church.
This list gives a comprehensive listing of pre and post-conciliar liturgical books in the Latin rite, including the rites of the religious orders and other such variants.
It is a very handy reference and includes explanations of how things such as the "Hymnarium", "Kyriale" and the like fit into the bigger Latin liturgical picture.
For those who have seen or heard of particular Latin liturgical references and haven't been certain what they are, or for that matter, what the different Latin designations are for the religious orders, this document will form a very pertinent reference.