Being effective is learning to do 'that which produces the desired result'. If you want to be extremely successful in business or very happy in life or achieve some large goal, then being effective is consistently doing the things that will bring about the results you are after.
Perhaps the best overall prescription for becoming effective is contained within
Stephen Covey's best-selling book The 7 Habits of Highly Effective People.
Published by Simon & Schuster, this book provides a useful, sequential framework
for understanding much about the process of Personal Development.