Early English Books Online (EEBO) contains digital images of over 125,000 works printed in England, Ireland, Scotland, Wales and British North America and works in English printed elsewhere between 1473 and 1700 - from the first book printed in English by William Caxton, through the age of Spenser and Shakespeare and the tumult of the English Civil War.
WorldCat is the world's largest network of library content and services.WorldCat.org lets you search the collections of libraries in your community and around the world. Includes books, music CDs, videos, digital content, and article citations, available in many languages.
"Epistolæ is a collection of letters to and from women in the Middle Ages, from the 4th to the 13th century. The letters, written in Latin, are linked to the names of the women involved, with English translations and, where available, biographical sketches of the women and some description of the subject matter or the historic context of the letter."
This is the place to start. Huge collections of well-organized primary texts, divided into: Ancient History, East Asian History, Global History, History of Science, Indian History, Jewish History, Medieval History, and Women's History
This blog is dedicated to the great manuscript scholar Léopold Delisle (1826-1910), and to François Duine, clericus dolensis (1870-1924), and (almost exclusively!) to medieval manuscripts, up to and including their relationships with early printing.