New Advent 
Besides hosting the Summa Theologica and the 1913 Catholic Encyclopedia, this site offers a Catholic FAQ, selected writings by the Fathers of the Church, and official Church documents, mostly papal, from approximately the last 250 years.
http://www.newadvent.org/Vatican Ecumenical Council II
Collection of Vatican II documents. Full text, with concordances and word frequency lists. Each chapter in its own file.
http://www.intratext.com/X/ENG0037.htm
Ad Tuendam Fidem
Issued motu proprio by Pope John Paul II on 28 May, 1998. Amends canon law. Preceded by a brief explanation of why this was necessary.
http://www.cin.org/jp2/adtuen.html
Code of Canon Law
Full text of the 1983 Code, with concordances and word frequency lists. Each chapter in its own file.
http://www.intratext.com/X/ENG0017.htm
College of Cardinals
Information on the men who choose the Pope, including a complete up-to-date list of Cardinals with biographical notes and statistics.
http://www.catholic-pages.com/hierarchy/cardinals.asp
Congregation for the Clergy
Extensive documentation on catechesis (includes the Catechism of the Catholic Church), priests, and deacons.
http://www.clerus.org/
Vatican Ecumenical Council I
Decrees of Vatican I. From the Tanner edition. With concordances and word frequency lists.
http://www.intratext.com/X/ENG0063.htm
Local Catholic Church History and Genealogy Research Guide
For those researching ancestors who were members of the Catholic Church, or who would like to know more about local Catholic history.
http://home.att.net/~Local_Catholic/
Largest Catholic Communities
Nations and U.S. states with highest numbers of Catholics; nations, U.S. states, and U.S. counties with highest proportion of Catholics; map of Catholic percentage of U.S. states' populations.
http://www.adherents.com/largecom/com_romcath.html
VaticanII.org: Power Search
Allows you to search the Catechism of the Catholic Church, the Catholic Encyclopedia, or the Holy See's web site, all from one page.
http://www.vaticanii.org/search/
Ethical and Religious Directives for Catholic Health Care Services
An electronic edition of the guidelines set forth by the United States bishops.
http://www.usccb.org/bishops/directives.shtml
Mass Times
Offers Mass times for the U.S. and other countries from information provided by diocese and individual parishes.
http://www.masstimes.org
