Body position: pool version: Here the body is 45 degrees to the line of the shot, the stance is moderately wide with both feet pointing 90 degrees from each other.
Body position: snooker version: Here the body is almost 'normal' to the line of the shot--that is 85 degrees from the line the cue ball will roll down. The feet are almost parallel.
In both cases, the head is over the cue, with the dominant eye over the center line of the cue. The Thorax is bent at the waist and the shooting arm is bent at 90 degrees, the forearm is straight down while the upper arm is level with the floor.
Holding the pool cue: The hand of the shooting arm is relaxed allowing the fingers to cup inwards and allowing the thumb to cradle the cue. For most shots one does not have to hold onto the cue as gravity will provide all the force necessary to hold the cue in your hand. If the gravity in your corner of the world does not provide such a force, you are shooting too hard.
The Bridge hand: The bridge hand is placed on the table. Most players put the palm of their hand on the table for added stability. The hand is rotated (somewhat uncomfortably at first) into the cue so that the index finger becomes the surface over which the cue shaft rides. The Pointing finger loops over the shaft, while the thumb supports the shaft from underneath. By and large, the thumb is used to control how high on the cue ball the tip hits while the pointing finger is used to control the shaft during the stroke. Many people have the end of the thumb and the end of the pointing finger touch and become a loop through which the shaft moves. The index finger is the fulcrum, the pointer and thumb the adjustments. The shooting hand can be used in addition to the bridge hand to control the angle of the cue into the cue ball. For now, try to get the cue stick as level to the table as possible.
The stroke: The stroke consists of a back swing and a forward swing, some people put a slight pause between the back swing and the fore swing. The important thing here is that the swing be smooth, without tension, the back swing should take at least 1 full second, and the fore swing about 0.7 seconds. This is fast enough to roll the cue ball down table and back up table. The tip of the cue must not move up or down, or right or left during this process. One way to develop a good stroke is to place an EMPTY coke bottle on the pool table and set up as if the mouth of the bottle were the cue ball. Then stroke through the mouth and all the way to the back of the bottle without touching the sides of the mouth. When you can do this 50 times in a row, it is time to hit the cue ball.
Hitting the Cue Ball: You want to hit the cue ball just above the exact middle of the cue ball (about 60%) this gets the cue ball rolling. So place the cue ball at the head spot and aim at the center diamond at the other end of the table. Take a nice slow stroke and make contact, sending the cue ball down table hitting the rail at the center diamond and bringing the cue ball back up table to where your still extended cue tip remains. If you don't hit the center diamond, something is wrong with your stroke. If you hit the center diamond but the cue ball does not roll straight back, then you are not hitting on the center line of the cue ball (that is you are putting side spin on the cue ball. When you can roll the cue ball up table bounce it off the rail and have it return to your cue tip, you are ready to start practicing shoots. BUT NOT UNTIL.
Making shots: Google up the Ghost Ball system. This system will explain where you need to make contact with the object ball to send it towards the pocket in an intuitive geometrical way. From straight in to about 45 degree cut angles, it works just fine, as you add more difficult cut angles, a touch of outside english is required to compensate for contact induced throw. So, for the first week of practice, just set up shots that are less than 45 degrees and shoot the shot (over and over and over) until you can do it reliably.
Practice: Practice is the kind of thing one does on the pool table when any missed shots will have the table returned to the previous position, and the shot repeated. I recommend that when you will a shot, that you shot it 10 to 50 times making each one of them before moving on.
Observation: Once the cue ball has left the tip of the cue, it is your DUTY to remain motionless and watch the cue ball roll towards the object ball, make contact with the object ball, and then watch the object ball roll towards the pocket. If you move your head you will not be able to see the subtle movements due to spin or table irregularities. You MUST watch the shot play out in order to understand what you may have done wrong, or what you have finally gotten right!
Play: it is what you do AFTER you can do the above.