[johnc]

Workout opposing and or complementary groups together. My routine is thus:

Day 1: chest - 12 to 15 sets, 6 to 12 reps per set.
back (opposing muscle group) - 6 to 9 sets, 12 to
15 reps per set.
Day 2: Shoulders - 12 to 15 sets, 12 to 15 reps per set
Triceps (complimentary muscle group) - 6 to 9 sets,
10 to 12 reps per set.
Day 3: Off
Day 4: Legs: 12 sets, 30 reps per set (this is nuts but I
had a knee injury 3 years ago and I've carried over
a modified routine based on my pt from then).
Day 5: Back: 12 to 15 sets, 12 to 15 reps per set.
Biceps(complimentary muscle group): 9 to 12 sets, 12
to 15 reps per set.

Each day I work abdominals for 2-3 different exercises, hitting upper & lower abs as well as obliques, each doing 30 to 50 reps with moderate weight (DO NOT DO SITUPS! It'll really place too much strain on your lower back). In addition, I try to work in 2 or 3 cardio sessions (treadmill) per week.

Now, you've probably noticed that I've hit my back twice in one week. I vary that routine by switching the 1st back/chest routine every other week so I'm concentrating on both groups "somewhat" equally. Chest and back IMO are very important to building overall size and developement to the upper body so I place extra emphasis thus.