Diet and exercise is different depending on your goals.  If you want to lose some weight, increase flexibility, increase muscular endurance, etc, crossfit is very good.  check out http://www.trainforstrength.com , they have some workouts posted on the site for free and it shows you how to do some of the exercises if you don't know how.  I keep it simple too, I used to train complete body 2 days a week, cardio (HIIT) 2 days a week, and friday(mix it up, work on some full body stuff like sets of burpees (AKA squat thrusts in the millitary), bear crawls, stretching, core conditioning.  Weekends off.  Have to get back to it, as I got out of it for about 1 1/2 years and packed on some serious weight.  Diet is crucial, crucial.  Eat healthy and smart.  For me, I eat 1-2 eggs and then 2 hours later fruit.  lunch low fat meat and lots of veggies, fruit snack later, then dinner.  I dropped 30 lbs in less than 6 months doing this.  PS.  take a mult-vitamin too.