Works

Epistle 2
Translated by John Henry Cardinal Newman and the Rev. Blomfield Jackson. In HTML, at the St. Pachomius Orthodox Library. To St. Gregory the Theologian, on monasticism.
http://www.voskrese.info/spl/basil2.html

Epistle 7
Blomfield Jackson translation. In HTML, at the St. Pachomius Orthodox Library. To St. Gregory the Theologian.
http://www.voskrese.info/spl/basil7.html

Letters
Blomfield Jackson translation. From A Select Library of Nicene and Post-Nicene Fathers of the Christian Church, second series, vol. 8. Each letter in its own HTML file, with a link at the top to table of contents. At Christian Classics Ethereal Library.
http://www.ccel.org/ccel/schaff/npnf208.ix.html

On the Spirit
Blomfield Jackson translation. From A Select Library of Nicene and Post-Nicene Fathers of the Christian Church, second series, vol. 8. In HTML, with notes, at Christian Classics Ethereal Library. 235K.
http://www.ccel.org/ccel/schaff/npnf208.vii.html

Prayer of St. Basil the Great
At the Orthodox Christian Page in America.
http://www.ocf.org/OrthodoxPage/prayers/basil.html