The Library of Ashurbanipal (also spelled Assurbanipal) is a collection of clay tablets recovered by Austen Henry Layard in the mid-19th century at the Mesopotamian city of Nineveh. The library included 25,000 clay tablet fragments adding up to about 1200 texts written in cuneiform. The texts cover information on all kinds of things-- including religion, bureaucracy, science, mathematics, poetry, medicine. The tablets were written during the Assyrian king Ashurbanipal's reign between about 668-627 BC.
Many of the texts involve recipes and technical instructions on how to do things, such as make glass and perfume. Also included were dictionaries and lists of proverbs. A version of the Sumerian Epic of Gilgamesh was also among the documents, as were myths, astronomical observations, prayers, administrative documents and letters.
Quotations from the Library of Ashurbanipal are found in several places in the Internet, including Babylonian Proverbs at the Ancient History Sourcebook ("The life of day before yesterday has departed today"). The Epic of Gilgamesh is available in glorious detail on the Ancient Texts site.
A brief description of the library is available at the Library of King Ashurbanipal Web Page. A few images of the tablets can be seen on the Sackler Gallery at the British Museum website, where many of the tablets are stored. Others are at the Iraq Museum of Antiquities and the Oriental Institute in Chicago.
British Museum welcomes Iraq library project (BBC News, 10 May 2002
Cogan, Mordechai and Hayim Tadmor. 1988. Ashurbanipal Texts in the Collection of the Oriental Institute, University of Chicago. Journal of Cuneiform Studies 40(1): 84-96
Shortland, A. J. 2007 Who were the glassmakers? Status, theory and method in mid-second millennium glass production. Oxford Journal of Archaeology 26(3):261-274.