The internet provides a lot of information concerning medieval manuscripts. We have assembled here some of the best sites so you will not get lost.
Early Manuscripts at Oxford University: Over 80 digitised manuscripts from the institutions of the University of Oxford.
Gallica: the Bibliothèque nationale de France have made an increasing number of their microfilms of medieval manuscripts available online. Some of the most famous manuscripts are also fully digitised in colour (in French).
Bibliotheca Palatina: One of the largest collections of medieval German manuscripts at UB Heidelberg, exemplarily digitised and completely made available to the public (in English and German)
British Library Catalogue of Illuminated Manuscripts: An online catalogue with some images of the codices and a very useful Glossary (in English).
Handschriftencensus: A digital catalogue of all known medieval manuscipts of the German speaking area (in German).
Archives de littérature du Moyen Âge (ARLIMA): An extensive and regularly updated reference portal with bibliographical information and useful links for the study of (principally francophone) medieval authors, texts and manuscripts (in French).
Mediaevum: An internet portal with lots of information around medieval German studies, manuscripts, bibliographies, pictures, medieval digital greeting cards and lots more (in German)