Military manuals are some of the best knowledge resources on the planet. These military manuals are written so anyone can understand them, and their topics range from demolition, survival skills and even boobytraps.
Army Field Manual - Booby Traps
Army Field Manual - Survival
Guerrilla Warfare and Special Forces Operations Manual
Army Technical Manual - Improvised Munitions Handbook
M1 Garand Manual
U.S. Army Silencers Manual
Rigging Manual
Operators AK-47 Assault Rifle Manual
Army Technical Manual - Incendiaries