The Crusades were a series of holy wars launched by the Catholic Church against the Saracens, or Muslims. In 1095, Pope Claremont inspired thousands of Christians to undertake the fight to retake the holy sites of the Middle East from the hands of the Muslims. These eight crusades were divided into two categories, with the first four being called the Principal Crusades, and the other four being called the Minor Crusades. There were several other expeditions, notably the Children's Crusade.
Regular Websites
Discusses the Crusades and pilgrimages as well as the People's Crusade and related items, including a Timeline of the Crusades from 350 to 1800 AD. - About.com: Dark Legacy
http://historymedren.about.com/od/firstcrusade/a/darklegacy.htm
Concise account of the Crusades, including the causes and ancillary information about Islam, the Catholic Church, and the Crusades themselves. - Crusades
http://kenanderson.net/bible/html/crusades.html
The Catholic Encyclopedia presents a lengthy article about the Crusades, its origins the foundation of Christian states in the east, and the destruction of those states. Goes into detail about each of those destructions. - New Advent: Crusades
http://www.newadvent.org/cathen/04543c.htm
Ransoming Captives in Crusader Spain
First published in 1986, this account of the Crusades, the wars, raids, and ransomings, the thirteenth-century Order of Merced, and the Mercedarian life. - Ransoming Captives in Crusader Spain
http://libro.uca.edu/rc/captives.htm
The Holy Land of the Crusaders
Delves into the Crusades, and presents images related to them, including sections about the journey to the Holy Sepulchre, the Garden of Gethsemane, and the Basilica of the Nativity in Bethlehem. There is an English as well as an Italian translation. - The Holy Land of the Crusaders
http://198.62.75.1/www1/ofm/crus/CRUmain.html
The Story of the First Crusade
Addresses the First Crusade, which began in November 27, 1095, and the account of the Second Pope Urban's part in it. Additionally gives accounts of various conquests, ambushes and sieges of that campaign. - The Story of the First Crusade
http://www.brighton73.freeserve.co.uk/firstcrusade/Overview/Overview.htm