Forget books. Buy ammo instead and go to a range. There is no substitute for range time.
A new shooter needs a starting point so he gets the basics right, without a good foundation he will quickly come to the conclusion that good pistol shooting is beyond him, or worse that handguns serve no practical purpose.
Much depends on the genre he'll be shooting in, but there are some elements that apply in all pistol shooting exercises. The gun should be held in a firm handshake grip, but not so hard as to cause tremors in the arm. The pistol should become a straight extension of the forearm, rather than cocked towards the thumb.
Stand quartering the target with your feet roughly shoulder width apart. Adjust your position until you find your natural point of aim. Think of a toy soldier and how you had to move him to get the rifle or pistol pointed at the target. To check your natural point of aim, check the sights against the target, close your eyes for a moment then see if you've swung off target when you open them. If you have to adjust your position, do so by moving your rear foot slightly and pivot on your front foot. To adjust your elevation move your feet slightly closer together or farther apart.
The front sight should be centered in the notch of the rear sight, and the height of the front sight should be even with the top of the rear sight. Once the sights have been correctly aligned on the target, the focus should shift to the front sight, allowing the rear sight and the target to blur. The front sight should be attached to the trigger finger, and unless you can see the front sight you should not make contact with the trigger.
Once the sight picture has been established the first pad of the forefinger should be placed on the trigger, and ideally there should be no contact with the frame of the gun, only with the trigger. The trigger finger does not squeeze the trigger, squeezing the trigger suggests something we don't mean, rather pressure on the trigger should be steadily increased until it breaks, and the new shooter must train himself to add pressure with his forefinger independently of the rest of his hand. This break should be a surprise, that is you won't know it s about to break until it does. You should not anticipate the break, although the break should not startle you. If you shoot an auto pistol, you must take yup the slack in the trigger without pulling the trigger right through the slack to the break.
Breath for each shot, do not hold your breath for a shot string. When you are about to shoot, hold your breath at the natural respiratory pause, without forcing all the air from your lungs, as doing so will cause your vision to blur quickly, cause arm tremors, and tempt you to rush the shot, You need to be relaxed and not tense up for the shot, it won't hurt you.
At home before you ever go to the range, dry fire your pistol until your front sight does not move off target with the trigger breaks. If you are shooting a rimfire pistol, use snap caps to protect the edge of the chamber. If your sights move off target, the bullet would have gone where the sights are now pointed. Be honest with yourself, and learn to call your shot.