If you want to spin the ball then you should twist your arm when you are pulling it back to roll the ball down the lane. Also, if you get back a little futher and walk more than two steps then it will give you a faster spin down the lane. It gives you speed.
When you hold the ball, you must put the ball in the palm of your hand. When you release it, spin the ball to the left, but make sure you throw the ball with some decent length (if you are right handed.... if left handed, spin it to the right)
First try using your thumb in the hole and layin other fingers outside the whole. The way you have to release the ball will cause the ball to spin. You can always turn your wrist 180 degrees as you are releasing the ball to get a back spin as well.
I will start with holding the bowling ball low with maximum wrist cup, a slow approach to the foul line and when i release the ball,i am lifting it but pushing it straight away. I don't force wrist motion other than using fingers to make a turning motion.
To spin the ball when bowling you must use your wrist. Aim the ball to the right of the pins and then when you bowl the ball, rotate your wrist counter clock wise. By doing this, it will put a spin on the ball that will then make the ball curve to the left.