Scoring/Serving

If the team that won the point did not serve the previous point, the players of the team rotate their position on the court in a clockwise manner. 

Types of Serves

The Underhand Serve

The underhand serve is simple—the player holds the ball in the hand opposite from the hitting hand, i.e. a right-handed player would hold the ball in the left hand. Hold the ball below the waist and above the knee so that with bent knees, the server is in good position to get the ball over the net.

For a right-handed player, the ball should be held still in the left hand, and the right hand should make a fist with the thumb on top of the folded-in fingers. The right fist should make contact with the underside of the ball, and the point of contact is on the palm side of the right hand, between the folded-in fingers and the wrist. Bring the right arm back and swing through to make contact with the ball and send it over the net. The left hand should hold the ball still; do not throw the ball up or move it. The underhand serve is mainly used for lower skill levels.

Overhand Serves: The Floater

Start with your feet. Put your left foot in front of your right, about shoulder width apart. Hold the ball at about eye-level with your left hand on the bottom and your right hand on top. The toss should only be high enough so that when you pull back your right arm, the hand contacts the ball on its downward swing. Toss the ball with your left hand; pull back your right arm as far as possible and swing—but not all the way through.

Stop forward arm swing and 'punch' the ball.

Stop the motion of your right arm when your hand contacts the ball, as if you’re punching the ball to the other side of the net, and don’t snap your wrist. This serve allows the ball to float and wiggle in the air. This makes its positioning on the opposite side of the court very hard to read, and it confuses people, making it difficult for opponents to return float serves.

Topspin

The beginning steps for the topspin serve are just like the floater, but the toss for the topspin must be higher. Toss the ball high enough so that the right arm can come down on the ball in a snapping motion on the underside of the ball.

It's all in the wrist.

Do not stop the motion of the right arm when it contacts the ball; rather, turn your shoulder away from the ball, swing all the way through and DO snap your wrist. Snapping your wrist will deliver a hard and fast serve to your opponent. This is very similar to a tennis serve.

Jump Serve 

This is a very advanced type of serve, and it should only be used at high skill levels. Instead of keeping the feet stationary, the player tosses the ball high in the air and takes a multistep approach to hitting the ball. Although the player may land in the court after the jump serve, the feet must leave the ground behind the end line to be legal. The motions are similar to the topspin serve, but they are done in the air. Jump serves are very effective, but they are often inaccurate because of the inconsistency of tosses.

Reference: http://iml.jou.ufl.edu/projects/Fall08/Devine/serving.html