The United States Marine Corps has produced some of the finest military manuals available today – and they are available on the Internet. Each is a lucid introduction –in clear, simple English, of its topic. The manuals are conceptualised as building blocks with MCDP 1 Warfighting as the foundation. Once the nature of warfare is understood, the reader is introduced to strategy, the operational level of war (campaigning) and tactics. Once grasped, the reader can next study the cornerstone concepts of intelligence, logistics, planning as well as command-and-control.
Below is a list of hotlinks to where they may be found.
US Army manuals
US Navy Manuals
US military dictionary