iam thinking about a management major. could anyone offer me some advice?

hi, iam planning to major in the management field when i start college. right now iam in the army currently in iraq. i either want to do business management or operations management. how much is the average salary a year for starting off? what kind of work am i going to expect? do u guys know any good books on management i could start reading up on? any advice would be much appreciated.