Ease Off
Many players think success in pool comes from hitting the balls as hard as they possibly can. The reality is that this rarely works, and a steady consistent stroke will provide more control and result in more balls going into the pocket. A resounding crack sounds nice, but control leads to winning.
Stripes or Solids?
In a game of standard eight-ball, a novice player should try to be the one shooting at the striped balls. The color contrast of the white field, the colored stripe and the number on the ball make it easier to effectively aim at.
Lining Up the Shot
Start lining up a shot by taking the cue and pretending you could use it to hit the object ball directly into the pocket. Determine where on the ball you would hit to make the shot. Then try to make that the spot where the cue ball hits the object ball. Getting close to the spot you aimed at will result in balls going into the pocket.
Spin
Top-notch pool players are able to put spin--often referred to as "english"--on the cue ball to make it curve or bend to the spot they want it to reach. While this is very difficult to learn, simple backspin and topspin are easy to apply and can greatly enhance an amateur's rate of success.
Backspin will stop the cue ball immediately after it hits the object ball. This is especially handy to stop from scratching when a ball is sitting right next to a pocket. Line up the shot the same way as always, but when you strike the cue ball angle the cue down slightly, hitting in the center but below the equator. That should cause it to continue in the line you wanted but with enough backspin to stop after impact.
The same principle applies to adding topspin to carry a ball forward after it hits the object ball. Line up the shot as always, but this time hit the cue ball above its equator. These are the two easiest forms of english to apply.
Don't Get Fancy
Expert players will try to not only sink the object ball with their shot, but also leave the cue ball in position to make another shot. For a novice, focus simply on averaging one made ball per turn. If you can do that successfully, you will win or at least come close to winning many pool games you play.