Article outlining the origins of the Inquisition and its Spanish and Roman variants.
http://es.rice.edu/ES/humsoc/Galileo/Student_Work/Trial96/loftis/overview.html
Extensive collection of documents from the Spanish Inquisition, maintained at the University of Notre Dame in South Bend, Indiana.
http://www.rarebooks.nd.edu/exhibits/inquisition/
Text of the Inquisition's charges against Galileo Galilei, provided by the Modern History Sourcebook.
http://www.fordham.edu/halsall/mod/1630galileo.html