Montana Military Museum, Fort Harrison, MT has a library and many artifacts from units of the 41st Infantry Division.
http://montanamilitarymuseum.org/

National Museum of the Pacific War, Fredericksburg, TX has a tank from the Buna battlefield and other related artifacts, plus a library.
http://www.pacificwarmuseum.org/

National Museum of the United States Army, Fort Belvoir, VA is not yet completed, but will include a soldier's registry and library facilities.
https://armyhistory.org

National WWII Memorial, Washington D.C. has a registry of WWII veterans
http://www.wwiimemorial.com 

National WWII Museum, New Orleans, LA has a digital collection which includes interviews with 41sters and artifacts donated by 41st veterans.  The new Road to Tokyo Pacific Theater Galleries is scheduled to open December 2015.
http://www.nationalww2museum.org/

Oregon Military Museum is currently under renovation, but contains many artifacts from units of the 41st Infantry Division and will include a library when completed.
http://www.oregonmilitarymuseum.org/

US Army Center of Military History has online catalog of publications and other information.
http://www.history.army.mil/

US National Archives and Records Administration
http://www.archives.gov/research/military/ww2/index.html

Washington National Guard "The Arsenal" Museum has displays on Camp Murray, Fort Lewis, and many artifacts from units of the 41st Infantry Division.
http://washingtonguard.org/museum/