since you are working out early, do your cardio AFTER your workout...
Dont just walk/cycle at the same speed for all 30min (or whatev time) ...
3min at one pace / 1 min at running from the boogie man pace ... back to 3min then to 1min hauling ass... the lowering and raising of your heart rate this way burns calories much faster.... you can get WAY more calories burned this way in 30 min than you could if you went at one moderate pace for an hour.
if you are working out later in the day/eve, morning cardio will work... but they need to be staggered half the day apart so that your body has chance to be loaded back up with food/energy... (ex: 7am cardio-5/6-7pm workout... and you can always do some cardio after your workout, no matter what time of day) got it? you just dont want to be energy depleted during your weight training.