first off, it takes a while to get used to relying on others to do work for you. It is really hard being responsible for work done by someone else.
That said, a good leader is good at listening and to a lesser extent talking. Coding is no longer that persons real responsibility.
I have found that one skill that is remarkable useful is to listen to someone explain their problem well enough to ask questions. More often than not, by asking the right questions the person can solve their own problems.
Changing to a leadership role means that you will be using a whole host of new skills. Unfortunately, unless you are good in those skills already you will have no idea of how well you are doing in the role.
To counter act this, it is best to try and get better at what you do every day, regardless of your perceived skill at it (this actually is good for any skill you care about). In fact, the article Unskilled and Unaware of it(pdf warning) by Justin Kruger and David Dunning helped me understand quite a bit about working with others.
A poor leader will assume they are "okay" at it.
Guidelines I use for judging if I am doing a good job is if I know what is going on and how individuals are feeling about the work. It is also a good indicator if the project is going well, but the feelings of the individuals on the project will usually be a good indicator of potential failure.
The people you rely on to do the work are, ultimately, the only thing that will determine your success or failure as a leader. If you can rely on your people you can step back and concentrate on serving their needs. If even one person is incompetent, you will be doing so much more work and it will be much harder.