The following are titles that I would heartily recommend for further study. I've uploaded book/chapter summaries for some of them, which you may read by clicking on the titles.
Apologetics
Gordon H. Clark, A Christian View of Men & Things
Gordon H. Clark, An Introduction to Christian Philosophy
Gordon H. Clark, Religion, Reason, and Revelation
Gordon H. Clark, Three Types of Religious Philosophy
Greg L. Bahnsen, Always Ready
Greg L. Bahnsen, Pushing the Antithesis - The Apologetic Methodology of Greg L. Bahnsen
Gary Crampton, The Scripturalism of Gordon Clark
Culture
Abraham Kuyper, Lectures on Calvinism
Carl F. H. Henry, The Uneasy Conscience of Modern Fundamentalism
Francis Schaeffer, A Christian Manifesto
Gene Edward Veith, Jr., God at Work
Gary DeMar, Myths, Lies & Half Truths
E. Calvin Beisner, Where Garden Meets Wilderness
Henry R. Van Til, The Calvinistic Concept of Culture
R. C. Sproul, Lifeviews
Gary North, Honest Money
R. C. Sproul Jr., Biblical Economics
James P. Gills & Ronald H. Nash, A Biblical Economics Manifesto
D. James Kennedy & E. Calvin Beisner, Overheated - A Reasoned Look at the Global Warming Debate
Ethics
Gordon H. Clark, Essays on Ethics and Politics
Greg L. Bahnsen, Theonomy in Christian Ethics
Greg L. Bahnsen, Homosexuality - A Biblical View
John Jefferson Davis, Evangelical Ethics
John Murray, Principles of Conduct
Samuel Bolton, The True Bounds of Christian Freedom
DVDs
Basic Training for Defending the Faith - A Five Part Video lecture series featuring Dr Greg Bahnsen. Produced by American Vision.
Global Warming - A scientific and biblical expose of climate change. Produced by Coral Ridge Ministeries and Answers in Genesis.
The Children of Caesar - This DVD contains two lectures: 1) Whoever controls the schools controls the world, 2) Getting your House in Order. The speaker Dr Voddie Baucham, Jr argues that Christian parents should take charge of the education of their children and stop turning them over to an ungodly educational system.
The Religion of Evolution - This DVD is a 45min lecture by Gary DeMar demonstrating that evolutionism is just as much a religion as Christianity. Unfortunately, the debate is often presented as one of science versus faith. This is simply not the case. As Greg Bahnsen once said, whatever you want to call Christianity, e.g. religion, theory, worldview, pre-committment, a priori etc, the same term can and should be applied to evolutionism.
