Medieval Manuscript Manual. This site offers basic information about Medieval Manuscripts, including their production, structure and function. There is also a glossary. The site was created by the Department of Medieval Studies at Central European University, Budapest.
Understanding Illuminated Manuscripts: A Guide to Technical Terms Illustrated glossary by Michelle Brown
How Parchment is Made (BBC video, 4 min): Wim Visscher shows Dr Stephen Baxter how to make parchment from animal skins
Making Manuscripts (Getty Center, 6 min video).
Making Manuscripts in Medieval England and France, 700–1200 (British Library).
BVMM: Bibliothèque virtuelle des manuscrits médiévaux , a virtual library of medieval manuscripts in French Libraries by the Institut de recherché et d’histoire des texts in Paris (IRHT-CNRS).
CERL Portal (Consortium of European Research Libraries): This database cross searches a number of European and Yale's manuscript collection catalogues as well as the Hand Press Book database, which lists books printed between 1450 and 1830.
DigiVatLab (Vatican Library): Access to the Vatican Library’s digitized collections: manuscripts, incunabula, archival materials and inventories as well as graphic materials, coins and medals, and printed materials.
Horae: Collection of Books of Hours (McGill RBSC): features Books of Hours in both manuscript and printed form, spanning several centuries from Rare Books and Special Collections at the McGill Library.
Illuminated Manuscripts (British Library): Manuscripts from the 8th to the 15th century.
Medieval and Early Modern Manuscripts Collection (Harry Ransom Center): The Medieval and Early Modern Manuscripts Collection contains 215 medieval or Renaissance manuscripts that date between the 11th and 17th centuries.