Said this before, and Matthew will get all "uppety" but DON'T start with Schenk. He is at least on some level controversial even in Presbyterian circles.

Start with the following:

Owen (cited by Matthew above)

Matthew Henry's treatise on baptism (little read, but perhaps the best thing out there - it was very helpful to me, and virtually EVERYONE in ministry respects Henry, so it will help with your pastor)

William the Baptist by James Chaney (it is online and is very heplful)

John Murray's Christian Baptism

The following link:
http://www.fpcjackson.org/resources/...heology/07.htm

__________________
Fredrick T. Greco
Senior Pastor, Christ Church PCA (Katy, TX)
Christ Church Blog

"The heart is the main thing in true religion...It is the hinge and turning-point in the condition of man's soul. If the heart is alive to God and quickened by the Spirit, the man is a living Christian. If the heart is dead and has not the Spirit, the man is dead before God." (J.C. Ryle)