John Johnson Collection of Printed Ephemera: http://johnjohnson.chadwyck.co.uk Many of the items have only a description and title, but many of them have images and that’s very intersting.
The Oxford Digital library has some other manuscripts. You can select which collection from the home page http://is.gd/nZVb then on the left menu you can choose “title” to open the series available. Once you see the page you can also zoom it to the tiny details.
More manuscripts and digitised images (Blockbooks): http://www.bodley.ox.ac.uk/csb/blockbooks_background.html
Something quite interesting… the internet biblia pauperum: http://www.amasis.com/biblia/index.html
And this is just another new feature in Google maps, Oxford is finally on the way to be virtually navigated: http://is.gd/o0b8