I would:
Be fair but firm.
Say Yes however you can while implementing No when needed.
Give people the benefit of the doubt until they prove otherwise—then act.
Give “the troublemakers” some kind of responsibility. All they usually want is validation in order to shine.
And for gawd’s sake, ban all “foodery.” Birthday cakes, announcement candy, holiday pot-lucks…in a group that large it’ll really pack on the pounds.
Unless they bring pie.
Not for me.
I’d rather be the court wizard–the guy who solves problems and supplies arcane knowledge–than the king. I don’t like being in charge, and I only take charge when it becomes apparent that no one else can or will. I can lead, I just don’t want to.
No. I’ve been a small boss and a medium boss, but never a big boss and certainly never the biggest boss. I don’t want to ever be a boss again, except for myself. Because even if you’re my boss, you’re not the boss of me! 
Seriously though, I won’t take a management position, ever again. I manage me and I produce results. I don’t know how to make other people produce results if they can’t do it on their own. I can share knowledge (in fact I like to) and I explain concepts rather than give answers, but I’m not a teacher and I’m definitely not a manager. It took a while for me to reach that conclusion because when you’re young, being a manager seems better than being a “regular” worker.
Dinsdale, I know you’re not a young guy and I’m sure your management environment will worlds apart from my own ancient history. You’re a few years older than me, but I have at least a bit of management experience. Take the following or leave it. It’s offered with sincerity and is basically what I would tell my 25 year old self if I could.
Go into this with the understanding that management may not be for you in the long run. If it doesn’t work out, you didn’t fail. You learned that most people aren’t meant to be managers. It’s better to realize this and walk away than to stay in a job that isn’t cut out for you. Once you’re doing the job, it becomes very easy to get into the mindset of “I can’t quit, I’m the boss!” It’s never true.
Your first week on the job, set a recurring appointment with yourself, twice a year. “Performance Evaluation - Me.” Don’t just delete the reminder when it comes up. Maybe postpone it until the weekend when you have some time to think, but honestly evaluate your performance as a manger and your personal satisfaction with the job. If you can get through a couple years of this, you can probably delete the appointment.
If you can be a good manager, you’re a rare person. There are a lot of managers in the world (most of them, I’d wager) who were very good at their jobs and a lot happier before they became managers. Some of them are good mangers, some are okay and some of them are shitty managers. Only the best managers are happier in their new roles than they were in their old ones. Personally, I probably hovered between okay and good, but I was never happier as a manager.
Check in with yourself, seriously. I could have saved myself a lot of misery if I would have gone into it as a test of a career path instead a commitment to one.
Best of luck!
Better yet, pee on everything. I learned that from my dogs. 
I’ve been the boss and it didn’t suit me. I don’t like getting my work done through others. I loathe motivating and policing people.
For the past 25 years, I’ve been a freelancing Lone Ranger. Much better. I ride in on my silver horse, do what needs doing, and ride out. I sell my time by the hour, and no one owns time they aren’t paying for. I have had regular clients, usually from 4 - 10 years. I NEVER have to attend any departmental meetings. I’d rather be working, and someone else can tell me anything I need to know about the content of any group meeting (usually there isn’t much content, as people on a salary waste time since they aren’t conscious of the tick-tock like I am). When my work is done, I leave. There isn’t enough money in the world to get me to be a boss again. Or even to be on a staff.
ETA: What Jake said.
I have no wish to ever be someone’s supervisor. I am, however, happy to be the person that everyone knows is the boss.
I hope that you don’t feel a need to leave a “legacy” behind. Few things are worse than change made just because someone wants to put a stamp on something, anything. Your staff could help the office improve, if you let them. They are probably well aware of the issues and may have many ideas for solving the problems. Change driven by staff may be more readily accepted than change from above, regardless of how much expertise the bosses have.
Also, no matter how expert you are in what your office does, bosses should not be doing the line work unless it becomes absolutely necessary*. Most folks don’t like to be supervised by someone that always has to work a project/case/client “just to keep my hand in.” If you are doing a stellar job on that project, you are probably failing as a manager. If you are doing great management, you don’t have time to work on that special project.
*I work in government, I know sometimes bosses ends up doing really stupid shit that they have no business doing, like managing active projects.
Related to “don’t do the work yourself”, I would add “don’t burn out your best people making doughnuts”. There is a lot of truth in the old saw of “If you want something done, give it to the busiest person in the office”, but I have seen a lot of energetic, reliable,competent people driven out of jobs because they got overloaded with all the less satisfying-but-important stuff because the boss prioritized being confident that that stuff would be done and done right. This gets worse over time as the competent, energetic, reliable people also become the holders of the institutional knowledge, so it’s so simple to assign that stuff to them; no explanations or training is needed. Give the new stuff to the new people, since they will be wasting some time training either way.
But reliable, competent, energetic people need challenges, and new ways to feel proud. And they don’t complain, they just find new jobs. And reliable, competent, energetic people generally can find new jobs once they start looking.
I have been in that position and I think I was good at it. Most of my work is done by other people since I don’t build the building, so I am used to having other people get me the end result I need. but even in-house I have been the boss on things, more later in my career before I decided to throw it all out the window and open my own shop. Now I am the boss but also the grunt–I prefer this.
However my advice would be to do a quick analysis on the lay of the land and (hopefully quickly) find the folks that aren’t producing. In my experience there is always one person who isn’t pulling his weight and the rest of the team knows it. What I find happens is that you have a productive team but they see this lazy SOB getting away with things that eventually you have a unproductive and unhappy team. If you can take decisive action and fix the issue you have a productive team. If you don’t take corrective actions then the team will fall back into the ‘nothing changes with new management’ and nothing will change. People will be looking to you for leadership.
Being an expert at what you do is good for the overall tone and direction of the office but being an expert on dealing with people is a skill that takes time to hone. I don’t think day to day your experience will come into play other than general tone and direction. If you try and micromanage I think you will be ineffectual.
Dealing with people is really the skill you need to focus on–I am okay at it, but my wife, damn she is fantastic at it. She isn’t afraid to have the talk with the person, she is firm and direct without being mean, and without letting emotion take over. She has the ability to keep her emotion out of it and just be direct and clear with what her expectations are and what steps need to be taken by the employee to achieve them, and if they aren’t met than what actions will be taken. I can do that but I struggle much more with it than she does. Odd thing is in our personal life it is reversed as I am much more direct than she is.
Good Luck!
I come from a Big-4 management consulting background. We use the terms “staff”, “time” and and “resources” interchangeably.
As a boss, think of yourself as Dale Earnhardt, Jr. Your staff are like the tires of your race car. You will burn through them and have them replaced without a second thought as they carry you around the track to victory! Maybe If they are lucky, the last remaining few that happen to be on the car at the end will appear in the background of a photo of you.
Don’t make the mistake of thinking that people who work under a CBA aren’t professionals.
Lots of good advice in this thread, btw.
Dinsdale, you know you’re one of my most favorite people, so I just wanted to wish you Good Luck! I know you’ll do a WONDERFUL job! 
I liked being the boss, but it takes a willingness to educate yourself in all the excruciating minutiae of the regulations that govern your piece of the pie (also personnel rules). Find the most knowledgeable person and shadow him/her. Take the policies/procedures manual home and read it many times. Become the go-to guy for all the answers, or at least know where you can find them. Find the biggest problems in the office and fix them quickly. Be the boss now and be friendly later. Take no shit.
One challenging thing about being “the boss” (or even an underboss… maybe especially an underboss) is that the “actual rules” for how an organization runs might be very different from the ones laid out in the official employees manual. And being a stickler for “the excruciating minutiae of the regulations” might actually be counterproductive.
That said, companies do have routine processes and procedures for doing things. The boss should be knowledgeable about those official processes and procedures as well as the “hidden” ones you need to know to actually get stuff done.
I like to think of it like this. Filling out schedules, Gantt charts, timetables and resource reports are an important part of managing a project. But by itself, it doesn’t get a project done successfully.
Remember that you are not actually the most important person on site; your secretary is and he or she was there before you and will likely be there when you’ve left.
I’d fire the cunt if I could. But I’ve got groundsfor being upset.
And to the OP: Being the boss will probably suck in new ways that you didn’t ever know existed. You’ll probably do things “wrong” for a while, and nobody will tell you, and when they do, it’s “You should know better!”
If I could find a better job with a fixed schedule like this one, I’d be a-movin’ on for sure. Being the boss sucks donkey nuts, because you can’t actually get shit done unless you’re actually the guy on top of the totem pole. Everyone else has to clear everything through that douche anyway.
See, it’s all peaches and bubblegum. 'Cept I hate bubblegum, and peaches just make my face all sticky.
And I’m not political. Can you tell? That’s all management is in this fucking world…political bullshit. If you can make other people like you, and tolerate their horrendous personalities and ineptitude, then you’ll do GREAT and everyone will LOVE you. If you’re a realist on the other hand, and can’t stand dumbasses being dumbasses, then you’re doomed to fail.
It’s not about what you’re able to do, or how well you’re able to do it. It’s about everyone else’s perception of your abilities. If they think you’re great, and you can support that notion with something (however wrong), then you’re a winner.
Sure thing. But you need to know what the rules are so you don’t have any major transgressions by you or your staff that will get you fired or reprimanded.
I haven’t been the boss all that long, but that’s actually one part of my job I don’t love. I have a great team - they largely manage themselves. However, having to deal with escalations when people from other teams aren’t doing their jobs or other teams think my people aren’t doing their jobs is a pain in the ass. Or figuring out what they don’t like about our current organization and trying to fix it in a company of 30,000 employees blows. That said, I LOVE helping develop people. It’s really satisfying and it’s awesome seeing employees improve in some areas and learn new strengths. It sounds silly and probably condescending, but I feel so proud of people on our team when they really shine.
Dinsdale, I hope you’ll come back to this thread in 6 months with an update as to how it’s going.
Ok, let’s start with the basics …
You need a riding crop.
You need a white stallion.
You a really LARGE fat cigar.
You need a bimbo.
You need a holstered pistol.
You need a large map on your wall with hundreds of pins stuck in it.
You need a megaphone.
Finally, you need both a gallows and a guillotine, so you can offer your employees some choice.
I think you’ll find that with these tools your leadership style will develop to its full potential.
Funny story. I worked as a mid-level manager at a Big Financial Services Company about 4-5 years ago. Since it was right about the time big financial services companies were falling out of favor, I had left for another job. 4-5 years later, I’m back at that same company leading a bunch of consulting projects for my firm. The only person left from my department was my former VP’s admin.
In fact, the only reason I didn’t quit that job after a week was that I became friendly with that admin and she was able to give me the inside scoop on how our unbearably psychotic VP would be “retiring” in a few months.
The moral of the story is treat your admin well because they are in a great position to tell everyone everything.
Thanks all. Been pretty busy preparing for this move, and suspect it will keep me pretty busy for a while after I start.
From everything I hear, it seems as tho there has been somewhat of a breakdown in organization and chain-of-command in the office I’ll be heading. As much of a pain it can seem at times to follow procedures, it sounds as tho this office is an example of why standard procedures ought to exist and be followed. While one ought not micromanage, I think the previous boss might have been a little too hands off for a little too long, resulting in folk forming factions, carving out their little spheres, and putting out fires as they arose by whatever means seemed necessary.
Right now someone I know well and trust is serving as temprary head, requiring strict adherence to policies, as well as regular and complete reporting. It should really help to have had this person run interference for me. I can require adherence to those transitional policies while I get my feet wet - and then as I get more comfortable and things sort out, I can retain or change what I wish.