For more great reading on the subject, check out these titles:
Astor, Gerald. A Blood Dimmed Tide. New York: Dell, 1993
Baldridge, Robert C. Victory Road. 1st Book Library, 2003.
Baum, Abe. Raid! The Untold Story of Patton’s Secret Mission. New York: Dell, 1981
Cole, Hugh. The Ardennes: Battle of the Bulge,
Dastrup, Boyd L. King of Artillery: A Branch History of the U.S. Army’s Field Artillery. TRADOC and the Center of Military History, Fort Monroe, Virginia and the Center of Military History, United State Army, Washington, D.C. 1993
Doubler, Michael., Closing with the Enemy. University of Kansas Press (Modern War Studies), 1995
Dupuy, Ernest. St. Vith: Lion in the Way. Nashville: Battery Press, 1986. (Official Division History of the 106th ID)
Eisenhower, John S., The Bitter Woods. New York: G.P. Putnam’s Sons, 1969
MacDonald, Charles B. A Time for Trumpets: The Untold
Story of the Battle of the Bulge. New York: William Morrow and Company Inc.,
Toland, John. Battle: The Story of the Bulge. New York: Random House, 1959.
Tolhurst, Michael. St. Vith: US 106th Infantry Division. South Yorkshire and Conshohacken, PA: Leo Cooper/Combined Publishing, 1999.
Merriam Press also publishes an incredible catalog of titles regarding the War. Check them out at http://www.merriam-press.com/.
Also, I used the Field Artillery Journal online database from the 1940s extensively for my research. They have issues stretching back to World War I. The articles are incredible and it was a great learning experience. I highly recommend checking them out at http://sill-www.army.mil/firesbulletin/archives/index.html.