Getting Contact Right
 

As a beginner, the first thing you must learn is how to make clean and simple contact with the ball. This requires making the racquet move in a straight line for about 4 to 8 inches near the time you strike the ball.  
Move the Racquet 4-8 inches without turning it.
 

The simplest way to do this is to shift your weight forward as you execute your stroke.

Lean Forward as you contact the ball.
Professional Player Making Clean Contact as the Strike the Ball

You can practice leaning forward with a partner as illustrated below.

Hold the racquet steady and lean forward

Below is a movie that illustrates the idea of moving the racquet in a straight line at contact/strike. Click on the image to see the video.

Correct Contact Motion

Below is a movie that illustrates the most common error that prevents clean contact. Note that as the stroke comes to an end, the racquet veers off the path of the ball as the player's arm continues turning across their body. Click on the image to see video.

Contact Error

Below we have overlaid these two movies to contrast the differences in the correct versus the incorrect movement.

 

Below are examples showing how professional players always make sure that they move the racquet in a straight line no matther what their situation.

Professionals get the contact right no matther how badly they are out of position