Vatican Sites:

• The Web Site of The Holy See.

• The Holy See Press Office.

• L'Osservatore Romano.

• Radio Vatican News.

• The College of Cardinals.

• Papal Encyclicals and Other Official Papal Writings

• Popes in the 20th Century.
  

The Roman Catholic Church in the United States:

• List of All U.S. Archdioceses and Dioceses Having Web Sites.

• Dallas Diocese

The Eastern Rites in the United States:

• Syro-Malabar Rite Catholic Church in America.
  

• Syro-Malankara Rite Catholic Church in America.

Official Roman Catholic Documents:

Catechisms:

• Catechism of the Catholic Church

• Baltimore Catechism for All Lay Catholics.

•  Nazareth Master Catechism:
  Parallel Presentation of Aquinas's Summa with the Trent, Baltimore, St. Pius X, and John Paul II Catechisms.

• The Cistercians - A  Benedictine Index