A few years ago I had posted a list with sites that have historical information for mission and campaign builders. Here's a reworked version of this list. I've also added numerous new sites that might also be useful for skinners or people working on maps and aircraft models for flight sims.


Finland

Finnish virtual pilots site with lots of historical information (in Finnish and English)
http://www.virtualpilots.fi/en/


Germany

Luftwaffe information (units, airfields, officer career summaries)
http://www.ww2.dk/

German Army in WW2, with large Luftwaffe section (in German)
http://www.lexikon-der-wehrmacht.de/

Luftwaffe in Norway
http://www.luftwaffe.no/

Information on German naval operations (in German)
http://www.wlb-stuttgart.de/seekrieg/chronik.htm

Axis history forum
http://forum.axishistory.com/

Luftwaffe blog
http://falkeeins.blogspot.de/

Biographies of German aces
http://www.luftwaffe.cz/

Luftwaffe site with lots of technical information, photos and original documents (in German, partially in English)
http://www.deutscheluftwaffe.de/

Another Luftwaffe site (in German)
http://www.luftarchiv.de/


Great Britain/Commonwealth

RAF
http://www.raf.mod.uk/history/index.cfm

Fleet Air Arm archive
http://www.fleetairarmarchive.net/

RNZAF
http://nzetc.victoria.ac.nz/tm/scholarly/tei-WH2AirF.html


Japan

Imperial Japanese Army and Navy Air Force
http://www.j-aircraft.com/

Japanese Army Air Force photo collection
http://ijaafphotos.com/

Japanese Navy Air Force photo collection
http://ijnafphotos.com/

Japanese Army and Navy aviation blog
http://www.aviationofjapan.com/


Romania

Romanian Army and Air Force in WW2 (available in Romanian and English)
http://www.worldwar2.ro/


Soviet Union

Soviet eastern front maps
http://www.armchairgeneral.com/rkkaww2/index.htm

Land-lease aircraft information (available in Russian and English)
http://lend-lease.airforce.ru/english/index.htm

Information on Soviet pilots, units and missions (in Russian)
http://allaces.ru/

Soviet aircraft information
http://mig3.sovietwarplanes.com/


United States

Large number of articles on WW2 operations by the US military, often with detailed maps
http://www.ibiblio.org/hyperwar/

US-Navy department communiques December 10, 1941 to May 24, 1945. Includes information about air operations
http://www.ibiblio.org/pha/comms/index.html

US-Army documents written during or after the war on all kinds of topics
http://cgsc.contentdm.oclc.org/cdm/landingpage/collection/p4013coll8

USAAF and US-Navy accident and MACR database
http://www.aviationarchaeology.com/src/db.asp

Combat Chronology of the USAAF
http://www.usaaf.net/chron/index.htm

Mustang units on Iwo Jima
http://www.506thfightergroup.org/

USAAF photos
https://www.fold3.com/title_495/wwii_us_air_force_photos/


Miscellaneous

Biplanes in WW2
http://surfcity.kund.dalnet.se/

Lots of information on fighter aces, for example Luftwaffe claims lists
http://aces.safarikovi.org/

Wrecks and airfields in the Pacific and much more
http://www.pacificwrecks.com/

WW2 aerial photos and maps
http://www.wwii-photos-maps.com/

German and Allied aircraft wrecksites in Norway
http://tihlde.org/~ktsorens/flyvrak/index.html

Luftwaffe and Allied air force discussion forum used by many well know experts
http://forum.12oclockhigh.net/

WW2 aviation forum
http://ww2aircraft.net/forum/

Aircraft database
http://www.aviastar.org/index2.html

Military history encyclopedia
http://www.historyofwar.org/index.html

Lots of military history articles
http://www.militaryhistoryonline.com/

Abandoned and little known airfields in Europa
http://www.forgottenairfields.com/

Collection of WW2 photos (in Russian)
http://waralbum.ru/

Pacific war encyclopedia
http://pwencycl.kgbudge.com/

Aviation history site
http://www.century-of-flight.net/

WOW! Thank you Juri_JS

Awesome list, thanks!