Finding a bat
The first thing you need to do is find a bat that suits you. The bat should be as tall as your hip when stood on the ground. The length may vary if you are a somewhat experienced batter and you know what length you like. Weight is a key issue when looking for a bat. As bat speed is key, a hitter should look for the lightest possible stick to swing, but keep this in mind: from a physics perspective, the formula where m1 is the mass of the ball, m2 is the bat, and v1,v2 are their respective speeds(i being initial, f being final). Wacky math aside, a heavier bat moving at the same speed as a less massive bat will empart more force on the ball, making the difference between a high fly, and a home run. An appropriate test for finding a bat of proper weight for your strength category is to hold the bat handle in one hand, parallel to the ground for 45 seconds. If you can hold it up, you should be strong enough to swing the stick. This is just a general rule of thumb. if you find your speed is too slow, shave two ounces off the bats' mass.
Gripping the bat
The grip the batter uses is important because it determines the bat speed. Your bottom hand should be placed half an inch from the knob of the bat. The “door-knocking” knuckles of you top hand should be roughly aligned with the "door-knocking" knuckles of your bottom hand. Reach back behind you and touch the head of the bat to your buttocks or your lower back. Now bring the bat around and hit the ground. Examine your knuckles and this is where you should try to have them. Remember to grip the bat loosely.
The Stance, feet
Lets first start from the feet and work our way up. This process is long and perhaps the most important to get right. First, you need to place your front foot about 6-8 inches away from the top corner of the plate. Place you back foot parallel to your front foot and about shoulder-width apart. Now tilt your front foot at a little less than a 45-degree angle. It should be pointing at about the space between the second basemen and the first basemen (given you are a right handed batter). Now bend your knees and transfer your weight so that about 75% of it is resting on your back foot. Also, always remember to be on the balls of your feet, and not flatfooted.
The Stance, body, arms, and head
Now that you have the feet set, next on the list is the rest of your body. Your hip, shoulder and head should all be pointing to the pitcher. The hands should be held around the batters dominant breast. The back elbow should be at a 45-degree angle downward allowing for the bat to be at a 45-degree angle across your shoulder. The top of your top hand should be in the general area of the top of your back shoulder. Your chin should be in the area between either on your front shoulder or about an inch from it, and your head needs to be still at all times. Make sure you are comfortable because you must be relaxed in order to be a great hitter.
The Stride and Load
A batters stride should be short and only about three to four inches. All you're going to do is take a little step forward and point your toes toward the pitcher, keep in mind that most of your weight is on your back foot. Now onto the load. In the load technique you should shift your upper body weight slightly back in order to get that extra bit of power before you swing. Note that the Stride and Load are done at the same time. Also, against a live pitcher, the batters stride foot should go down as well as upper body weight shifting back at exactly the same time as the pitcher's front foot hits the ground. This is done in order to help your timing and reduce the risk of getting thrown off by a curve or change up.
Head action and ball tracking
The batter's head needs to be perfectly still and he must watch the ball from the pitcher's hand to the time it hits the bat. Your chin should transfer from your front shoulder to your back shoulder during the swing of the bat. You should make connection with the ball out in front of your body. Note that this all takes place during the swing.
After the load and stride the next step for you is to swing the bat. The swing should be in a straight and slightly downward motion, always keeping your hands on the inside of your body. While this is happening the batter's back foot should pivot and the hips would turn forward so they too are now facing the pitcher. At the same time your hips are completely forward, the bat should be parallel to the ground and about waist height with both arms fully extended on a downward slant. This is where the point of contact should be.
Extension and Finish
After the point of contact, your arms should extend to shoulder height. At this point your wrists will involuntarily flip over and the bat should be pointing at the left fielder (given again that you are a right handed batter). Even during and after the extension, your head should still be looking at the invisible spot that was once the point of contact. The final step is to let the bat carry itself over your shoulder and run to first base.