Union Presbyterian Seminary has recently published several audio lectures and sermons from John Leith, professor of theology at Richmond for three decades and a fine interpreter of the Reformed tradition. He loved the Reformed tradition in all of its breadth, whether Calvin or the Westminster Assembly or Karl Barth. The lectures can be found at the Foundation for Reformed Theology.
A good place to begin is his lecture at Columbia Theological Seminary’s Alumni Forum: “The Reformed Perspective,” from 1978. You can stream or download (right click).
As for books, his Introduction to the Reformed Tradition is still the best all-around introduction, serviceable to a broad audience. Your next stop should be his Assembly at Westminster: Reformed Theology in the Making.