Loads of free talks in MP3 here
http://www.proecclesia.com/page_free%20talks.htmVen. Fulton Sheen's catechism series, especially good for converts
Fr. Hugh Thwaites's readings of the New Testament, Imitation of Christ, the Way of the Cross, the Penny Catechism, and various encyclicals. Also his tals on the Mass, Confession, and the Rosary. Last but not least, his WWII memoirs of his conversion and time as a Japanese POW. I really can't recommend Fr. Thwaites's talks enough!
Enjoy!