zmx,
Both jelqing and stretching are fundamental exercises for length. If your new, try this routine:
A routine for the beginners to start growing. It has helped a lot of beginner's gain anywhere from .25 to 2.5 cm of length in two weeks. After the two weeks you can take a break or increase the intensity to 1 on, 1 off. Whichever you choose.
Good luck!