"If you believe what you like in the gospels,
and reject what you don't like,
 it is not the gospel you believe, but yourself."
-- St. Augustine

Church documents

Papal Encyclicals Online -- Encyclicals and other papal documents, plus Vatican II and post-conciliar documents.

Catholic Encyclopedia (1913) -- Summa, Church Fathers, etc. at New Advent.

Code of Canon Law (1983)

Elcore.net -- Bibles, Church documents, and various writings.

Church documents collection at CatholicGoldmine.com.

Defending the Faith

Biblical Evidence for Catholicism -- Maintained by Dave Armstrong and highly acclaimed by Catholic and non-Catholics alike; hundreds of sources on almost any Catholic apologetics topic.

Biblical Foundations International -- a ministry that demonstrates to Catholics and non-Catholics alike the scriptural case for Catholicism. Founder and President Gerry Matatics was the first Presbyterian Church of America minister ever to become Roman Catholic; several have since followed him.

Catholic Answers -- This Rock magazine and other apologetics information.

Catholic Apologetics, History, and Doctrine

Catholic Apologetics International -- President & Founder: Robert Sungenis; audio tapes of talks and debates; downloadable articles; books; speaking schedule.

Catholic Documents and Apologetics -- Major Catholic Super-Sites / Catholic Resources and Search;  Periodicals; Catechisms; Official Church Documents; classic Catholic Writings (mostly by Saints).

Catholic Internet Yellow Pages -- Brother Raymond, of the Monks of Adoration, maintains this site with huge number of links.

ScriptureCatholic.com -- provides over 2,000 Scripture citations from the Old and New Testament that explain and defend the teachings of the Catholic Church.