The Catechism of the Catholic Church and the Compendium direct from the Vatican.
A wonderful site packed with great resources to truly understand the Catholic Christian faith.
Keep up-to-date with this news site full of articles from various Catholic sources. Also contains the Catholic Encyclopedia, the Summa, the Church Fathers, the Bible, as well as many Vatican documents.
The official website of the United States Conference of Catholic Bishops. Also includes The New American Bible, Revised Edition (NABRE) online.
The official blog of Cardinal Timothy Dolan of the Archdiocese of New York.