The Professional Billiard Instructors Association (PBIA) Instructor Manual lays out a teaching order: equipment and mechanics first (stance, grip, bridge and stroke), then aiming and a shot routine, then cue ball control and side spin, then pattern play, with the break, advanced shots, strategy and the mental game after that. This section is organized the same way, so if you are new, read it top to bottom.
Most of the physics and measurements here come from Dr. Dave Alciatore, a mechanical engineering professor at Colorado State University who writes on pool physics and technique in Billiards Digest, alongside published instructors. Each page lists its sources at the bottom.
Where most players go wrong
Dr. Dave's list of the ten most common faults is a useful map of what this section fixes: an elevated cue, an unstable bridge, the head too high, the head out of alignment with the cue, moving the eyes and cue at the same time, a weak pre-shot routine, side spin that was not needed, a tight grip, a rushed or elbow-dropping stroke, and moving the head or body during the shot. Almost every one of them is a mechanics problem, which is why the mechanics pages come first.