Hey man I just started working out too! Best thing to do is develop some sort of weekly routine. I read one of the dummies books and based my routine off that. Its not the greatest routine, but its adequate for beginners like me. You won't find me working my sternocleidomastoids directly, for example (those exercises look like they'd snap my neck!)
My routine:
Day - Routine - Time - Muscle Groups - Exercises
Monday - Upper Body Push - 1:10 - Chest and Triceps - Warmup run, Bench Press, Incline Chest Fly, Vertical Press, Dip, Triceps Pushdown, Triceps Kickback
Tuesday - Upper Body Pull - 1:00 - Back and Biceps Warmup run, Lat Pulldown, Dumbbell Pullover, One-arm Dumbbell Row, Concentration Curl, Preacher Curl
Wednesday - Lower Body & Support - 1:20 - Shoulders, Abs, Lower Body - Warmup run, Shoulder Press, Back Delt Fly, Leg Press, Leg Extension, Leg Curl, Thigh Machine, Ab Crunches
Thursday - Cardio - 0:30 - Cardiovascular Run
Friday - Push + Shoulders - 1:30 - Chest, Triceps and Shoulders - Warmup run, Bench Press, Incline Chest Fly, Vertical Press, Dip, Shoulder Press, Back Delt Fly, Triceps Pushdown, Triceps Kickback
Saturday - Pull + Lower Body and Abs - 1:50 - Back, Biceps, Lower Body and Abs - Warmup run, Lat Pulldown, Dumbbell Pullover, One-arm Dumbbell Row, Concentration Curl, Preacher Curl, Leg Press, Leg Extension, Leg Curl, Thigh Machine, Ab Crunches
Sunday - Yoga and Stretching - 1:00 - Whole Body