speaking of imbalances, watch out for chest exercises. if you look at the typical person these days (who in fact spends hours in front of a computer), you will notice a hunched over posture. what this means is that the chest muscles are in fact TIGHT and need to be stretched while upper back muscles are stretched and need to be strengthened.

also if you are seated all day, hip flexors and hamstrings are also muscles that are tight and need stretching.

the squat is an amazing exercise, i would suggest beginners start with squats with the ball (against the wall).

the fact is everyone is different, and i highly recommend going to a personal trainer a) to learn the proper exercises and form, b) to come up with a program that is more specific to your goals as well as your body type.

good luck!

Hannah