I am looking for documentation or book references that explain in particular the reason behind some of the changes in the liturgy after V2, specifically the changes in the Roman Liturgical Calendar as well as why the names of the canonical hours in English were changed (from Vespers to Evening Prayer, for example).
I would bet that folks at The New Liturgical Movement blog could assist you here.
The best book for calendar changes in English would be “Norms governing Liturgical Calendars” part of the USCCB’s “Liturgy documentary series”. It has a translation of all the explanations that appeared in Notitiae, the publication of the Concilium, and later the CDW. Some of the mtaerial and principles have been sacrificed , most notably in the 2002 General Calendar, but it will give you a good place from which to start.
It’s out of print, so if you can’t find it, let me know and I’ll see what I can do by way of scanning, or something.
Look at the collections of post concilar documents that are available.