For what is now considered a "side-show", the Aleutian campaign was horrendous. The weather alone killed and injured more than battle casualties. And yet it's amazing the efforts and achievements of the US, for example, in their building of roads across Alaska.
The best book on the subject is
The Thousand-mile War: World War II in Alaska and the Aleutians
Some more links:
Naval perspective
http://www.navy.mil/navydata/cno/n87.../forgotten.htm http://www.ibiblio.org/hyperwar/USN/...Aleutians.html
Army perspective
http://www.ibiblio.org/hyperwar/USA/USA-C-Aleutians/
And excellent WW2 documentary:
http://www.archive.org/details/Repor..._The_Aleutians
Another recent release
http://www.alaskainvasion.com/home.html
And associated with the campaign:
http://www.microworks.net/PACIFIC/ba...ki_islands.htm