I found a *wonderful* book for reference for world war 2 uniforms, this one is for USA:
The World War 2 GI Uniforms 1941 to 1945 In Color Photographs by Richard
Windrow and Tim Hawkins.
I can not believe all the pictures and
information in this book. The pictures in this thing are so good I got
itchy from looking at the wool uniforms. It goes through all the
different uniforms in all the different theaters from the helmets and
the different linings inside the helmets, right down to the different
boots. If you haven't seen it, please check it out, as it's great help
for noobs like me who have no clue as to what i'm doing.
This is some of the things they discuss/show pictures of in the fall/winter of 44 chapter:
Reversed OD field Jacket; EM's special wood trousers; EM's wool melton
overcoat; M1943 field jacket. trousers and cap; M1941 wool toque' M1943
hood, oficers and EM's double texture raincoats; sweaters, long sleeved
five button, sleeveless crew neck. long sleeved V neck. first. second
and third pattern mackinaws; OD wool and leather gloves, trigger finger
mittens; carbine magazine pockets; marching compass and pouch; M;1938
wire cutters; M1936 field bag musette; M1938 dispatch case. M1917
binocular case, SCR 300 radio, M3A1 45 Cal sub machine gun...
I'm serious, the pictures are amazing.