US Navy
Naval History and Heritage Command: By Sea, Air, and Land
From the Department of the Navy, this site provides a detailed description of naval activities and strategy during the war in Southeast Asia. Great maps and pictures too.
PBS
People's Century: Guerrilla Wars
Col. David Hackworth, in an interview on PBS, relives the mindset of the leaders during the Vietnam effort. His accounts reference how the war of attrition affected the mentality of both those serving the US and those at home.
Digital History
Digital History: Fighting a Guerrilla War [Pdf]
Read the personal memories of U.S. Vietnam veterans who talk about fighting against guerilla warfare that was carried out by the Vietcong. The accounts are touching and thought-provoking. [pdf]
PBS
Pbs: Battlefield Vietnam: Guerilla Tactics: An Overview
This site from PBS describes guerrilla tactics used by the Viet Cong with a close up of Cu Chi, a tunnel system near Saigon.
Other
Vietnam War Commemoration: The u.s. Army in Vietnam, 1954 1973 [Pdf]
Article on U.S. Army involvement in Vietnam, 1954-1973, as part of the Vietnam War Commemoration.
Other
Vietnam War Commemoration: The u.s. Coast Guard in the Vietnam War [Pdf]
Article outlining the U.S. Coast Guard involvement in the Vietnam War.
Other
Vietnam War Commemoration: The u.s. Marine Corps in the Vietnam War [Pdf]
Article celebrating the U.S. Marine Corps and outlining involvement in the Vietnam War.
Other
Vietnam War Commemoration: The u.s. Navy in the Vietnam War [Pdf]
Article commemorating the U.S. Navy and their role in the Vietnam War.
PBS
Pbs: Battlefield Vietnam: Air War
This PBS Battlefield Vietnam site describes the airplanes used by the U.S. to carry out the air war in Vietnam.