My master, Master Harold von Aurebach has graciously sent to me a little list of books he reccomends. I will pass them along :).
1: "Illuminated Manuscripts and Their Makers" by Rowan Watson is published
by V&A Publications (2003), 160 Brompton Road, London SW3 1HW ISBN
This is a very good overview of many different styles of initial
letter and border decoration taken from manuscripts in the V&A
2:"Tesori Miniati" by Maria Gatti Perer and Maio Marubbi (1995) Silviana
Editoriale is published by Amilcare Pizzi S p A of Milano, and is
another overview of medieval and rennaissance from collections in Bergamo and
Brescia, Italy. What I really like about this book is that most of the
examples seem to be Italian, so it is a way of following the development
of scripts and illumination styles and tracing influences from other parts
of Europe. I managed to pick up my copy from a street vender, but I
believe the publisher's price is 30 or 35 Euros.
3: "Miniatur del '400 a San Marco" by Magnolia Scudieri and Giovanna
Rasario (2003) was published for the Firenze Musei by Giunti Gruppo Editoriale
(no address), ISBN 88-09-03202-0. This accompanied a manuscript exhibition
at San Marco and is valuable for two main reasons: There are a number of
examples of unfinished initial letters, which allow you to see the
stages of work, and there are a number of examples of initial letters which are
decorated with light blue on dark blue acanthus leaves, with shading and
white work creating a three dimentional look.
The first book on the list can be bought through amazon.com ( link on right side bar)I am still trying to track down where to find the other two but I suspect abebooks will be a good source.