Take hold of the top of the club in your left hand. Place the small finger of your right hand in the space between the middle finger and forefinger of your left hand. Make sure your thumbs are aligned down the shaft of the club. Grip the club firmly but not tightly. Say you were holding a tube of toothpaste. If you were squeezing it correctly, toothpaste would come steadily out of the tube. Not spurting, but steadily. Squeezing the club too tightly will have a negative impact on your swing. You want to be able to swing smoothly, but a tight grip usually promotes a harder swing that leads to poor contact and an errant shot.
Put the club in your left hand and slide it up to the top of the grip. Take the small finger of your left hand and place it under the forefinger of your left hand. Make sure your thumbs are aligned down the shaft of the club. This grip gives a golfer the best chance for distance. It takes some getting used to because of the unnatural position of your small finger under your forefinger. To get used to it, go to the driving range and hit a bucket of 40 to 60 balls. The key to finding success with the interlocking grip is to break your wrists on impact with the ball.
Hold your golf club in your left hand. Put your right hand directly under your left hand as if you were holding a baseball bat. Your hands will not work together as they do in the overlapping or interlocking grip, but there will be freedom. This is the grip that many golfers consider to be the most comfortable, and many golfers start out using it before moving to the overlapping grip. One of the advantages of the baseball grip is that the golfer can snap his wrists naturally at impact. It can help promote significant distance, but it may be hard to control and keep it in the fairway.