Business is comprised of two most important parts - the working part which runs the day-to-day processes of the business and another, the management one. The working part has most of its work well-defined and elaborated by the other part. Business management is an important factor to run a business efficiently because it makes strategies and defines business goals to be fulfilled in long run.
Business Management is not an easy task, one wrong decision and you are gone with the storm. Even calculated risks are calculated again and then taken.
Managing business properly is a skill which anyone can learn and upgrade through proper learning channel and direction, but it should also be kept in mind as stated in various Business Management Books that "you can't do business today with yesterday's method and hope to be in business tomorrow again". Business strategies are very much dynamic in nature they keep on changing from time to time.
Business Management comprises of deep understanding of core business processes and terms like BPR (Business Process Reengineering), Law of Averages and TQM, etc. How one process of the system is related to others and modifying one process can influence others.
These things should be kept in mind. Big companies even got a dedicated team called Change Management teams which are solely dedicated to the process of business change and its after-effects.
To join the business as a management part one should first groom his base with general concepts and techniques used in day to day business via researching over internet, studying various Articles On Business Management and books, etc. Though the person should have a feel and foresightedness to see beyond the fog.