I have put links here to websites that have good online resources for ancient and medieval history.
Here is the link for Google Translate. It is a surprisingly decent online translation tool- http://translate.google.com/
The website for the Society for Medieval Military History. It has lots of articles on medieval military history, reviews of books, and links to primary sources- http://www.deremilitari.org/
Website of Episcopus: The Society for the Study of Episcopal Power and Culture in the Middle Ages. It has links to primary and secondary sources on Church history- http://www.episcopus.org/
British History Online has a number of primary and secondary texts of value for British History- http://www.british-history.ac.uk/Default.aspx
The Online Reference Book for Medieval Studies- http://www.the-orb.net/
The Internet Medieval Sourcebook has links to numerous primary texts in translation- http://www.fordham.edu/halsall/sbook.html
The Internet Ancient Sourcebook has links to numerous primary texts in translation- http://www.fordham.edu/halsall/ancient/asbook.html
The Internet Modern History Sourcebook has links to primary texts in translation- http://www.fordham.edu/halsall/mod/modsbook.html
The East Asian History Sourcebook has links to primary materials in translation- http://www.fordham.edu/halsall/eastasia/eastasiasbook.html
The Camelot Project at the University of Rochester is an online portal for primary and secondary materials on King Arthur- http://www.lib.rochester.edu/camelot/cphome.stm
Luminarium provides links to literary source material- http://www.luminarium.org/
Netserf is an online clearing-house of links to websites regarding medieval topics- http://netserf.org/
Durham Cathedral Muniments. A website of scanned images of medieval documents for palaeographical study- http://www.dur.ac.uk/medieval.documents/index2.htm
Website of the Wheelock Latin Series- http://www.wheelockslatin.com/
Website of the Texas Medieval Association- http://pages.towson.edu/duncan/tmahome.html
Website of the Charles Homer Haskins Society- http://www.haskins.cornell.edu/
Website of the Medieval Academy of America. The Links page is especially helpful- http://www.medievalacademy.org/
Medievalists.net is a website about, by, and for medievalists- http://www.medievalists.net/
A really cool interactive map of the Roman world allowing you to calculate shipping times and distances between various points- http://orbis.stanford.edu/