This is the basic text for understanding yoga, particularly if you follow Iyengar style. It describes how to get into and out of each pose, provides photo "plates"...old timey ones with Iyengar himself, has numerous appendices including a suggested schedule for incorporating various poses from beginner to advanced. Includes background on yoga...its a wonderful reference for me as a beginner. Only drawback is that it doesn't seem to include too many variations for beginners (use of props et cetera, which is weird given that Iyengar is really known for its use of props.