Old has written a surprising amount of really good books. I enjoyed his highly informative and well researched Worship: Reformed according to the Scriptures

Along those same lines, you may want to pick up another work that I have found profitable (although I haven't yet finished): The Shaping of the Reformed Baptismal Rite in the Sixteenth Century

And if you are enthralled by the history of preaching, you absolutely must pick up the currently six volume (seven now?) of The Reading and Preaching of the Scriptures in the Worship of the Christian Church. There is nothing else out there with its scope and engaging style of writing. There are ministers included of whom you haven't ever heard mention made in church history courses (as well as all of the expected "big fish"), but who he has uncovered in his years of research, an of whom he gives evaluation of their style and approach from their extant manuscripts. He very interestingly and often insightfully sets their preaching within the social and ecclesiastical circumstances of the minister's time, and discusses approaches to preaching (such as festal, catechetical, expository, etc.) as well. You should pick this up if you do not already have it.

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Adam J. Myer
Waiting on the September accessions board.
Evergreen PCA
Salem, Oregon