I very much agree. The purpose of practicing yoga is to develop ones energy body in order to experience other dimensions of life and wellbeing. This kind of energy can not be transmitted via a book or any video channel, unless you are a master with other power. Therefore I highly recommend learning from a well trained teacher. The yoga i teach and practice is growing in popularity, its called Isha Yoga. Its classical and pure and allows you to develop your own home practice, safe in the knowledge you are doing it all absolutely correctly, which is key.