First-time managers are generally nightmares to work for. They are people who got promoted by doing a non-management job well, and in fact they probably have little experience in management. Here are four of the mistakes that will undermine a new manager the fastest.

1. Focusing on tasks instead of people.
Before you were a manger, your number one job was to accomplish tasks. You were someone with skills to get something done. Maybe media buying, or programming, or selling. Now your number one job is to help other people to accomplish the tasks in an outstanding way.

Sure, you'll have tasks, too. As a manager you'll have weekly reports, budgets, planning. But your tasks are secondary to helping other people to do their tasks. Your job as manager is to get the best work from the people you manage. The measure of how well you're doing as a manager is how well each individual on your team performs.

Ideally, you should be able to show each person you manage how to see themselves differently so that they are able to produce at a higher level than they ever imagined. For one person this will mean you need to teach organization skills. For another person, you will help her discover what she loves to do and then set her up doing it for you. Each person wants something, and you need to find out what that is. Then help them get it.

In return, your employees will do great work for you. This level of management is superior to task-management; helping people perform at their best impacts the quality of your team's work as opposed to just getting the work done.

2. Being slow to transition.
Moving into any new position requires that you get rid of the stuff from your old position. This means delegating. It means getting over the idea that you were indispensable on any of your old teams. You can't do you new job well if you're still doing your old job.

Delegating your old job should take three days. You find people who are taking a step up when they accept pieces of your old job so that they are excited. You give them an explanation of how to do it and tell them where to go when they have questions.

You are going to tell me that one day is not enough, that you have a very complicated job. But think of it this way: If you died today, your job would be delegated in a couple of days.

Delegating is not enough, though. You have to stop caring. If you are no longer on a project because you got a promotion, then you have to stop obsessing about how the project is doing.
Remember how quickly the girl who dumped you hooked up with her next-door neighbor? You need to move that fast, too.

3. Forgetting to manage up.
Managing up means steering your team to hit goals that the people above you care about. Figure out what matters to your boss, and your boss's boss, and make that stuff matter to you, too, because you can only impress your boss with your management skill if you are accomplishing things she cares about.

And be loud about your accomplishments. Set measurable goals for yourself and let people above you know that you're meeting them.

Do this it right off the bat. People's perceptions of you as a manager will be made during your very first actions. That saying, “People judge you in the first two minutes they meet you,” is true for management, too. So give people reason right away to think you're doing a good job.

4. Talking more than listening.
My sister-in-law, Rachel, has been a manager for a while. But she just accepted a position where she is managing three times the number of people she had been managing. Her first step was to go on a sort of listening tour of the organization. She had lunch with people to find out what matters to them, she sat in on groups and even visited some people at home, all in the name of figuring out what matters to whom, and how she should set up goals for herself.

Consider your own listening tour as soon as you start in a new position. After all, there's no way to figure out what people want without getting them talking. And the most annoying thing about any manager — new or seasoned — is when they just won't shut up.