Fr. John Zuhlsdorf at What Does The Prayer Really Say gives a brief synopsis of the origins of today (and from where I found the photo--fedora doff to the good priest).
At the 'blog of Ignatius Press is a re-post (see, I am not the only one who does this) from an excerpt of a book by Dr. Peter Kreeft, a professor of philosophy at Boston College.
Speaking of priests, Fr. Philip Neri Powell, OP, who has his own 'blog (Domine, da nihi hanc aquam!) shares his homily.
Finally, there is my post from 2006 which links to a post from the Happy Catholic.
Originally posted 9/29/2012.