If you don't have time to do cardio. The best routine to lose weight, and build some muscle would be a circuit. Moving from one excercise to another using moderately heavy weights. Such as doing flat bench presses for 10 reps, then bicep curls, then leg lifts then shoulder presses, then low pulley rows, then tricep press downs. The idea is to keep your heart rate up while working each muscle group and giving each group a small rest. This is how I started by doing this routine three to four times a week I spent no more than an hour each time in the gym. Each day I would the same muscle groups but with different exercises. Its a good starting point to build some strength but also strengthen the most important muscle you have.