Ambrose: Concerning Virgins
Book 1, Chapter 2 of this treatise tells the story of St. Agnes. From the Nicene and Post-Nicene Fathers of the Christian Church, second series, vol. 10. In HTML, with notes, at Christian Classics Ethereal Library.
Catherine Fournier
Three accounts of the life of St. Agnes: for children ages 0-8, children 8-14, and age 14-adult.
Catholic Community Forum
Illustrated hagiography of St. Agnes, with quotes from the Fathers.
Catholic Encyclopedia
St. Agnes of Rome, virgin, martyred at the age of 12 or 13, revered since at least the mid-fourth century.
Catholic Online
The story of St. Agnes. Suitable for children.
Gallery of Western Orthodox Saints
An icon of St. Agnes, virgin-martyr of Rome, with explanation.
James Kiefer's Christian Biographies
St. Agnes of Rome, martyr. With prayer in traditional and contemporary language.
Lives of Saints
St. Agnes of Rome, virgin, martyr. From the book "Lives of Saints", published by John J. Crawley.
Lives of the Saints
St. Agnes, virgin, martyr. From Alban Butler's Lives of the Saints.
Patron Saints Index
Profile of St. Agnes of Rome. Illustrated.
Saints for Young Readers for Every Day
The story of St. Agnes, for children.
Shonnie Scarola
Hagiography of St. Agnes.
The Ecole Glossary
Short essay on St. Agnes of Rome, by Karen Rae Keck.
The Life of St. Agnes
By Ælfric. Modern English translation by W.W. Skeat.
Zenit
News report of the seminarians of the Colegio Capranica being urged by John Paul II to imitate their patron St. Agnes.