Questions about chakras?

The Self Realization Fellowship in Los Angeles sends lessons by mail and teach you Kriya Yoga..to rise up the serpent in the wilderness...to bring you up to the higher chakras, I don't know much about them, but I know the effects of Kriya, great joy, enhanced senses, greater understanding, the experience of bliss...they explain everything, I just like doing the Kriya because of how it enhances my life.