After you've spent some practising stroking her clitoris, you might want to try it during sex. Some positions lend themselves well to this, some don't. Here's some good ones:

The X-Position

This is where the man lies on his back, facing upwards. The woman lies on top of him, also facing upwards. She lies at an angle to him, so that her head, shoulders and feet rest on the bed, but her butt rests on him to make sex easy and comfortable. Click the diagram to enlarge:

Raised X-Position

This one is similar to the X-Position but the woman raises herself up to get more tension on her g-spot.