This is my routine, its not perfect but it works for me:
Sunday: Cardio
Monday: Weights (quads, calves, hamstrings)
Tuesday: Cardio
Wednesday: Weights (biceps, triceps, shoulders)
Thursday: Cardio
Friday: Weights (Chest, back, abs)
Saturday: Rest day
Twice a week I train in Muay Thai as well.
Before I joined a gym cardio, consisted of skipping and running around the block. I do weights at home with just a pair of dumbells.
But the cold weather has sent me indoors so now cardio consists of treadmill, rower, bike, eliptical machine in random order for a random time (minimum of 10 mins)
All sessions last around 50-60 minutes, with stretching at the end.