Pilates is good for you! Pilates is a wonderful way to increase flexibility, muscle tone, bone mass and posture. One of the major benefits of pilates is that it increases the tone of your abdominal muscles. This can do wonderful things for your posture. Improving your posture can help your back, hips, knees and ankles feel better even if you don’t lose any weight. Pilates also helps you become more aware of your posture, helping you to be mindful of your body alignment in everyday life.

From WebMD.com

-quote
Many types of people, at many levels of fitness, who have begun doing Pilates exercises say they've seen improvements in range of motion, flexibility, circulation, posture, and abdominal strength -- and decreases in back, neck and joint pain.
-endquote

While you don’t need to learn all the pilates forms before you start, I do highly recommend you start pilates in a class or with a video before practicing it on your own with or without a pilates machine. An instructor, either on a video or (preferably) in person, can help you get your forms right when you’re first starting out.

In order to understand the basics of Pilates and why it can work for you, you first need to understand where Pilates came from. Joseph Pilates is the man that marked the beginning of the history of Pilates and a new method of exercise began.

Susceptibility to asthma, rheumatic fever and rickets left Pilates weak and frail as a child. Pilates was extremely motivated to strengthen his body and overcome his physical obstacles. Not yet a teen, Pilates began researching many types of exercise to aid in his strength-training program.

Joseph first developed the mat exercises and these are the foundation of the entire Pilates Method of body conditioning. Joseph Pilates devised a unique sequence of movements that worked the mind and muscle in harmony.

History of Pilates - http://www.pilates-shop.net/history-of-pilates.htm