[thompo]

learn the basic compound lifts with a barbell - squat, deadlift, bench press, overhead press, clean, and row

learn a routine and stick with it - some suggestions are:

mark rippetoe's starting strength (http://aasgaardco.com/store/store.php?crn=199&rn=312&...)

westside for skinny bastards (http://www.defrancostraining.com/articles/38-articles/60-wes...)

bill starr's 5x5 (http://madcow.hostzi.com/5x5_Program/Linear_5x5.htm)

you'll get more bang for the buck out of a real weight lifting routine with some added cardio or barbell complexes (google the cosgrove evil 8) rather than a mostly cardio based routine. cardio by nature is catabolic - it is nearly impossible to maintain muscle mass while training cardio heavily. instead, focus mostly on lifting weights to alter your body composition (build muscle, improve posture, burn fat) and using cardio to supplement that with increased endurance and overall cardiovascular health. the optimal cardio to pair with weight training is HIIT (high intensity interval training) - basically sprint training. if you need any reason for this, compare photos of a marathon runner with a 100m sprinter and you'll see the obvious differences in body composition.

if you want to look like an athlete you need to train like one, period. fitness should a complete lifestyle change, not a weekend hobby.