You will find stretches for almost every single muscle in your body. Diagrams of each stretch show proper stretching technique and where the tension should be felt. The book runs through each of the main stretches, suggests a program for everyday stretching, and has a number of sport-specific programs. Yes, the pencil diagrams are corny, but as soon as you get over that, you will realize there is a wealth of information in here.
Should you do yoga or stretching? Yoga w/ a tape or a class is certainly a mind/body event that many people enjoy as a part of their fitness routine. But for a fitness regimen, a 20 minute stretching routine every morning or night has advantages over yoga. Yoga is essentially stretching exercises combined with isometric weight resistance. But yoga can often overextend or place undue stress on the ligaments/tendons and often the positions are not stretching the full length of the muscle, and if they are the positions often stretch the muscle to its limit immediately, rather than gradually, which has been shown to provide better flexibility results. With regard to the isometrics, if you are looking to build strength and/or muscle you need the progressive weight resistance that free weights or machines will provide - the isometrics will not provide significant results.
Stretching on a regular basis (along w/ aerobics and eating right) will leave you feeling relaxed and energized and if there is one stretching book you should own, this has got to be it.