During a search of an Al Qaeda member's home, police in Manchester, England, found a document described by the FBI as the Al Qaeda training manual. The manual was found in a computer file described as "the military series" related to the "Declaration of Jihad." These excerpts describe the structure of a military organization whose main mission is the "overthrow of the godless regimes and their replacement with an Islamic regime," and include instructions on counterfeiting and forgery, security measures for undercover activities, and strategies in the case of arrest and indictment. The manual was translated into English and introduced as evidence in the embassy bombing trial in New York in 2001. Further excerpts are available at the Department of Justice website.

Excerpts from the U.S. indictment of Zacarias Moussaoui which was filed in December 2001. Moussaoui is the alleged "20th hijacker" in the Sept. 11 attacks and this indictment offers information on what U.S. authorities know to date about bin Laden's Al Qaeda organization. The full indictment is available at the Department of Justice website.

After being convicted for his conspiracy to blow up the Los Angeles International Airport in December 1999, Al Qaeda-trained terrorist Ahmed Ressam agreed to cooperate with U.S. prosecutors in hopes of a lighter sentence. In July 2001, he appeared as a witness for the prosecution at the New York trial of co-conspirator Mokhtar Haouari. His testimony offers chilling details of exactly how an Al Qaeda terrorist cell operates and what went on in Osama bin Laden's terrorist training camps in Afghanistan.

U.S. authorities learned a lot about the workings of Al Qaeda in the January 2001 trial of four bin Laden associates for the bombing of the U.S. embassies in East Africa. The government's case against the bin Laden operatives was based on the testimony of two key witnesses -- Jamal Ahmed al-Fadl and L'Houssaine Kherchtou -- who provided detailed testimony about Al Qaeda's structure and inner workings.

Three months after the Sept. 11 terror attacks, J. T. Caruso, acting assistant director of the counterterrorism division of the FBI, testified before Congress on the history of Al Qaeda, its ties to other terrorist organizations, and what U.S. authorities learned about the structure and capabilities of Al Qaeda from the East Africa embassies bombing trial.

PBS's NewsHour offers streaming video and a transcript of its report on the intricacies of Al Qaeda, its financial network, its recruiting practices, and its ties to other terrorist groups. The report features interviews with New York Times correspondent Judith Miller and Harvard University lecturer Jessica Stern.

The Financial Times website provides an interactive map showing what investigators know about Al Qaeda cells and financial centers around the globe, as well as a collection of reports on the terrorist network.

Time.com offers a rundown, with pictures, of bin Laden's top lieutenants and their associates.