http://www.fordham.edu/halsall/sbook1.html : The Internet Medieval Sourcebook is an excellent collection of primary sources on diverse topics.
http://omacl.org/ : The Online Medieval & Classical Library allows you to search for primary sources, or browse through them by author, title, genre, or language.
http://www.learner.org/exhibits/middleages/index.html : An easy-to-read and navigate introduction to life in the Middle Ages, covering Feudalism, religion, homes, clothing, health, arts, and urban life.
http://www.the-orb.net/ : An extensive website, the On-Line Reference Book for Medieval Studies is largely composed of secondary sources.
http://womenshistory.about.com/library/bio/blbio_list_medieval.htm : An A-to-Z collection of biographies on some of the Medieval and Renaissance periods' most notable women.
http://www.fordham.edu/halsall/medfilms.html : Brought to you by the same people as the Internet Medieval Sourcebook, this is a rather comprehensive and annotated guide to films about the Middle Ages, from Sergei Eisenstein's Alexander Nevsky to Ridley Scott's Gladiator.
http://www.medievalmap.net/ : An interactive map of Europe from AD 362 to AD 1483, showing shifting political boundaries, the migration and invasion patterns of tribes and nations, the growth and development of towns, historic battles, and links to websites for learning more about the topics involved. Requires Flash.
http://www.the-orb.net/non_spec/fiction.html : A list of fiction books set in ancient and medieval times, from the On-line Reference Book for Medieval Studies.
http://www.besthistorysites.net/Medieval.shtml : If you're still not sated, the Best of History Web Sites' section on Medieval History has even more webpages for you to explore.
http://www.besthistorysites.net/EarlyModernEurope.shtml : While its page on Early Modern Europe has a number of Renaissance-related sites for your perusal.