Swami Sivananda was one of the most important figures in the recent development of yoga. His pupil Swami Vishnu Devanda went to San francisco in 1957 and eventually established an international network of Sivananda Yoga Centres.
Swami Vishnu synthesized the ancient wisdom of yoga into five principles
and this 'step by step complete guide' is structured around these principles.Proper relaxation, physical, mental, spiritual, is an essential part of yoga practice, necessary for meditation and ultimate self realisation.
At the beginning of practice, lie in the Corpse pose, stretch the body and let gravity pull it down deeper into relaxation. Breathe deeply.
At the end of practice, lie in the Corpse pose, go through the body, tensing and relaxing every part.
Basic sequence is provided (pages 66-67), with timings. The sequence can be elaborated, and additional poses added.
Breath is life. To a yogi, proper breathing has two functions, to bring more oxygen to the blood (and brain), and to control vital energy (prana), leading to control of the mind in preparation for concentration and meditation.
Useful diagram of the chakras, page 71.
Energy has three qualities (gunas), purity (sattva), activity and passion (Rajas), and darkness and inertia (tamas). The qualities exist together in equilibrium, but one type tends to predominate. Foods can be classified under these headings. Sattvic foods pure) are preferred - cereals, fruit, vegetables, dairy products, legumes, nuts.
Meditation is a continous flow of perception or thought, like the flow of water in a river. In order to see the Self you must first learn to still or control your thoughts, to become master of your mind, instead of it being tossed about by senses, fantasies, desires. During meditation you observe the thoughts of your mind and become dispassionate about them.
The two main types of meditation are saguna (with qualities) and nirguna (abstract, without qualities). In saguna, meditation involves considering the meditator separate from the object. In nirguna, the meditator and the object are one.
Time, place, posture, breathing, technique, mantras, tratak (steady gazing) are all important to successful meditation, and ultimately to self realisation.