Heres ways that you can divide up the muscle groups, like Pushing and Pulling, or Upper and Lower body. In the Push/Pull method, you do the "pushing" muscles together and the "pulling" muscles together.
PUSHING...............................PULLING
Chest...................................Back
Shoulders..............................Biceps
Triceps.................................Abs
Calves..................................Legs
If you were to break them up into Upper and Lower body groups,
UPPER...................................LOWER
Chest....................................Legs
Back.....................................Calves
Shoulders...............................Abs
Biceps
Triceps
As you can see, the Upper body seems to have a lot more work to do, but if you work your legs hard, the Lower body day could be your most difficult to survive. Both of the groups above work well, but I prefer to group my body parts like this in a split routine:
TORSO...................................LIMBS
Chest.....................................Legs
Back......................................Biceps
Shoulders...............................Triceps
Abs.......................................Calves
6 day split routine would look like using a push/pull grouping.
MONDAY.....TUESDAY.....WEDNESDAY.....THURSDAY.....FRIDAY.....SATURDAY
Chest.........Back...........Legs...............Chest............Back.........Legs
Shoulders....Biceps........Calves.............Shoulders.......Biceps........Calves
Triceps.......Abs..................................Triceps..........Abs
A 5 day split routine is almost the same as the 6 day, you only train legs one time a week.
MONDAY.....TUESDAY.....WEDNESDAY.....FRIDAY.....SATURDAY
Chest.........Back...........Legs...............Chest........Back
Shoulders....Biceps........Calves............Shoulders...Biceps
Triceps.......Abs.................................Triceps.......Abs
Thursday and Sunday would be your days off.