Catholic Answers:
■ The Rise of Catholicism ■ And Then Along Comes Mary
Also:
■ Does Matthew 28:19 Prove the Trinity < (a biblical study about the name of Jesus)
■ Perspective On Trinitarian Terms < (the Trinity was not taught by the early Church)
■ Who Is Jesus Christ? ... < (Trinity refutation / Jesus Christ is not God the Son)
Links:
Catholic Encyclopedia — comprehensive online Encyclopedia @ NewAdvent.org
Catholic Library — comprehensive online Library @ NewAdvent.org
The Fathers of the Church — list of Church Fathers @ NewAdvent.org
Catholic Answers Forum — the largest Catholic Community on the Web
Catholic Answers — Exposing Catholicism: Crisis of Faith