The overlapping grip is the one used by more players than any other and is designed for accuracy. In order to grip the club in this manner, take hold of it in your left hand and put it about 1/2 inch from the top of the club. Wrap your fingers around the club and have your thumb going down the shaft. Now take the small finger of your right hand and put it in the space between the middle finger and forefinger of your left hand. Align your right thumb down the shaft of the club as well.
The interlocking grip was used by Jack Nicklaus and is designed to give the golfer maximum power. Take hold of the club with your left hand and put it at the top of the club, no more than 1/4 inch down the shaft. Your left thumb goes down the shaft while your fingers wrap around it. Take the small finger of your right hand and place it under the first finger of your left hand. Your right thumb goes down the shaft.
This grip gives the golfer more comfort and freedom when gripping the club. Take hold of your club as if it were a baseball bat. Your left hand should be at the top of the grip and your right hand should be directly underneath it. Both of your thumbs are wrapped around the club instead of going down the shaft.