Here is a very brief intro into position play. (for all purposes here, ENGLISH refers only to sidespin, topspin is FOLLOW, and backspin is DRAW)
1.They angle of the shot dictates the direction of the cue ball takes off the object ball (if you are cutting the object ball to the right, the cue ball will go to the left and vicaversa)
2.Sidespin only directs the cue ball off the rail, not the object ball. Which is to say, sidespin doesn't make the cue ball do anything other than spin UNTIL/UNLESS it touches a rail. Then the cue ball will go in the direction of the sidespin. English does not effect the angle the cue ball comes off the object ball (not discussing throw).
3. Follow and draw control the tangent line. If the cue ball arrives at the object ball with no top or back spin (cue ball is sliding) on a cut shot, the cue ball will follow a line 90 degrees from the line of centers of the shot. This perpendicular line is called the tangent line. If you have follow (topspin) on the ball on the cut shot, it will go forward, away from you, of the 90 degree tangent line. If you have draw (backspin) on the cue ball on the same shot, it will it will come behind the tangent line, back towards you.
4. Distance on a shot, straight in or close to straight in, depends mainly on the speed of the stroke. On cut shots, its still the speed of stroke that determines the speed, but the fullness/thinness of the hit needs to be taken into consideration. The fuller the hit, with a certain stroke speed, the slower the cue ball will move after the hit. The thinner the hit at the same stroke speed as before..... the faster the cue ball will move after the hit. This also applies to the cue ball hitting the rail after a shot. Reverse english (sidespin opposite the angle of the cue ball coming off the object ball/entering the cushion) will slow it down off the rail.
There are only a few principals to learn about position play. The thing is, there are countless combinations of spins and speeds you can put on the cue ball on a shot. The best advice is to set up a simple cut shot, mark the position of the balls (those 3 hole paper reinforces work well) so that you have the same shot each time. Then start experimenting with.... where does straight follow make the cue ball go..... where does follow with a touch of sidespin make it go...... etc etc etc. Position play is limited only to your creativity and skill for speed control. A good stroke and some chalk doesn't hurt either.......
Chuck