For quite some time now I have been recommending a six part series on Baptism by Edward Donnelly. Rev. Donnelly is the pastor of Trinity Reformed Presbyterian Church, in Northern Ireland. He is also the Principal and Professor of New Testament at the Reformed Theological College, Belfast. Edward Donnelly is one of the finest preachers alive. If you have not heard him, I recommend every sermon he has at Sermon Audio. But you really must listen to this series on baptism:

Baptism #1

Baptism #2

Baptism #3

Baptism #4

Baptism #5

Baptism #6