I found the Hacker's Diet a useful reference for both diet and exercise. I found its engineering-minded explanation of how the body uses food resonated with me. (I lost about 50 lbs. in 6 months). Link: http://www.fourmilab.ch/hackdiet/e4/

There's also a small section on practical daily exercises that can be done quickly, without need for equipment. I'll link directly to that: http://www.fourmilab.ch/hackdiet/e4/exercise.html

The key to both diet and exercise, however, lies in consistency -- you have to apply yourself every day.