This is an old revision of the document!
When writing missions or creating addons it's often a good idea to have real-live references to work from.
Here are some of the sites that can serve for 'inspiration':
Australian Army Videos
Military.com
MilitaryMorons.com
MilitaryPhotos.net
US Army Videos
ArmyRecognition
Military acronyms on Wikipedia
Globalsecurity.org
Olive Drab
Jedsite requires registration
Jane´s Armour and Artillery requires registration
DefenceTalk Picture Pallery
Army Field Manuals
Communication Procedures
Radio Procedures
U.S. Marine Corps Training Manuals
United States Military Rank, Pay Grades & Insignia
DeicideNBF's Gallery
Security Arms' Gallery
World.Guns.ru
World of Heckler & Koch (HK)
SigArms (switzerland)
FAS' Guide to U.S. Land Warfare Systems
FAS' Guide to U.S. Navy Ships
FAS' Guide to U.S. Navy Shipboard Combat Systems
FAS' Guide to Non-U.S. Land Combat Systems
FAS' Guide to Non-U.S. Naval Forces
Prime Portal
Motorfahrer