I have made up a list of the seven most important muscle groups, ranging from greatest importance to least importance, when it comes to adding size to your upper body.
The first muscle group that comes to a beginner's mind when considering which muscle group will give he or she the well-developed look of a bodybuilder is usually the upper arm and more specifically the biceps. This is probably because when someone asks to see your muscle, most people don't go and flex their beefy deltoids; they flex their biceps.
The idea that adding bulk to your arms will give your entire upper body a major increase in size is a common misconception that many beginners have. The muscles of the upper arm only make up a small part of the upper body, and although a nice set of arms may look good during the summer months, they don't really add much size to the upper body.
The deltoids contribute to both the front and back of the upper body and if they are not well developed your entire upper body will suffer. Some exercises that will help to develop the deltoids are dumbbell side laterals and front dumbbell raises.
An exercise that will help to develop the pectorals is the bench press; the bench press works the entire pectorals. Another exercise that will help develop the inner pectorals is the narrow grip bench press.
The traps will also contribute to the classic V-shape that everyone wants their upper body to have. Some exercises that will help to develop the traps are the military press and the standing barbell press.
In addition, a well-developed pair of triceps will contribute greatly to chest development since the share many of the same exercises. Some exercises for the triceps are the narrow grip bench press and triceps extensions.
The biceps may not add much size to your body but if well-developed, they can pull together a lacking physique and are necessary for any bodybuilder.
No one wants to go the beach and after all his or her hard work have everyone be distracted from his or her great body by a fat gut. The key to great abs is a low body fat percentage. Most males will be able to see their abs at around 8% or below and females at around 15% or below.
Crunches will help to tone the abs but I do not recommend using weight because you will get a gut full of abs. This may look all right at the beach but when you have your shirt on it will just look like a beer belly.