Start with a military manual for raw basics. Supplement with YouTube for visual confirmation. And when you are ready, step off the PDF and onto the mats of a local dojo—because the real magic of martial arts isn't found in pixels or paper; it is found in the sweat on your brow and the respect you give your training partner.
A hypothetical PDF would cover:
Focus on using hands, feet, knees, and elbows to strike an opponent.
Stick to library loans or low-cost used copies—you’ll get a clean, complete, and legal version.