When I was earning my MBA, I heard a lot of students talk about books they had read which taught quick rules of business and management. One of the most popular is The One Minute Manager, by Kenneth Blanchard (PhD) and Spencer Johnson (MD). It often seems as though everyone knows this book, yet it's pretty obvious that most managers are, hmm, less than outstanding. I also noticed a certain, well, arrogance among young people that they will become masters of their industry simply because they get a nice shiny degree from Important University. While I agree that education is important, and so is certification, for some things you really need the voice of experience. You can get that in two options - you can learn it by trial and error, or you can find someone who's been there and is willing to share their knowledge and experience. That can happen in four ways; you can pay for a class where someone with experience teaches what they know, which is one reason the really expensive schools charge so much; you can hope that your company will assign you a mentor; you can ask around and try to find experienced business professionals on your own; or you can listen to the veterans in your company and field. You might be surprised to find how many people with long experience are willing to share what they know - their motive is surprisingly generous and kind, actually. Most companies, speaking bluntly, either don't train their managers to be managers (somehow, companies never seem to grasp that promoting a person who has education or does a job well, does not necessarily mean that they can manage a team or show leadership just because they're promoted), or that training is less than what you need. A lot of veterans, on the other hand, can you tell you about your most important customers and clients, how to avoid the political hot potatoes that show up sooner or later, and - very important - what you do well and what you do not do well, and how to deal with the different personalities, skill sets, and personal goals of your team.
There are a lot of 'one minute managers' out there, who have learned maxims and clever insights that made them feel ready to do their job. But the really good managers, in my experience, listened to the 'twenty year managers' available to them, even when those "managers" were their subordinates.