[ptero]

This is a hard switch that requires you to focus much more on personal / people challenges and much less on technical challenges. I recommend you completely throw out your developer hat. Your role on technical issues should be limited to making decisions when necessary.

Otherwise I would focus on three things:

1. Estimating project time. It will now be your problem when things are not on schedule. Nothing happens quite as planned, but knowing when your team can realistically deliver X is priceless. Successful mastery means most projects get completed in line with your internal predictions (which do not have to match whatever your own management expects or claims).

2. Keeping team happy. Knowing each team member strengths and interests, understanding and resolving interpersonal problems. And keeping them shielded from your own management. Successful mastery means your team respects you.

3. Firing (and to a much less extent hiring). Learn when you should let someone go and how to do it. Success means you have to do it rarely and when you do you do not lose team's respect. They may grumble, but deep inside will know that this is the right decision.