German Reformed Liturgy Debates
For many years now the history of Reformed worship has been one of my "hobbies." Lately I've enjoyed reading Maxwell's Liturgical Lessons of Mercersburg. It's in dissertation format and type, but nonetheless a good read. And I noticed that D.G.Hart is coming out with a book on J.W.Nevin. I'll probably wait til it's out in paperback.
For more background on the RCUS and Mercersburg, see David Koyzis' posts of 7 Jul 03 and 8 Jul 03.
There's also a helpful comparative chart of various historical Reformed orders of worship on page 24 of the Ordained Servant, vol.3 no.3 [in PDF only].