Bibles in the Middle Ages were usually written in Latin, although translation into common (vernacular) languages was becoming popular as people became more literate.
The Lindisfarne Gospels
The British Library’s “Turning the Pages” display on the Lindisfarne Gospels has shown the immense progress technology has afforded manuscript studies. There has been an incredible amount of research done on these gospels; here is a website that provides some self-tutorials about them. These 8th century gospels are in Latin, but over the Latin script there is what is called a gloss--an explanation or translating assistance in a common language, in this case Old English.
‘The Corpus Irish Gospels’
These gospels are from Corpus Christi College at Oxford University. The scans of this 12th century manuscript are in high resolution and is very simply decorated. The department of Early Manuscripts at Oxford University has many medieval manuscripts that are worth looking at, some of them scientific texts.
Codices Electronici Sangallenses
The Library of St. Gallen has a number of bibles in their collection, which can be found by their search engine--unfortunately, I can’t link directly to them here because of the frames on the website. They are easily found, though, as most of them are labelled “Bible” followed by the texts in the volume.
Latin Vulgate Bible Online
This website exists to help you read the Bible (Jerome’s Vulgate) in Latin; it has search capabilities, two English translations, and tools for saving phrases and verses for later use. It would be a good idea to bookmark this website if you don’t intend to learn Latin seriously but are still interested in being able to recognise specific passages within a manuscript.