With a developer mindset, what helped me was this (no particular order)
* Go about it as a problem solving task. This can be as complex and fun as building a new system - you are building organization and culture. The way you treat them will mirror in how they treat each other and your customers.
* Don't assume too much what a manager should do or what you have seen, but see your new job as an enabler of other people and find out what the particular needs there are. You're the user interface for other people to get things done in the company.
* The hardest thing is probably to stop solving implementation problems yourself. That's again an enabling position. All the stuff you were the expert in before you now need to transfer to other people. Don't just quickly solve their new problems because you know it better.
* One thing about micromanagement - If there's something that appears to be micromanagement, it's often a problem of too little actual management and not enough. That sounds weird, but the reason is that management interferes with people's work directly, where they actually should have given them the tools and the knowledge to do it themselves. So when you start hearing or sensing that notion, don't stop managing, but try to find out where you really need to help.