You want a manager who can, well, manage. If they spend more time coding, or debugging than managing you have a problem. I know, I know development managers code, right? No. A manager, a real manager, manages. They keep your inbox a plenty, and help you handle any issues you have with the work, people, or tasks.
Where I work now, we have our manager then comes the project lead, and then we have the senior level developers and engineers working on the specific project. Our manager is rarely seen, or heard from, but he's working to keep us busy, focused, and happy. Yep, happy. My manager calls me to ask how I am, what I need, and if I like my work. Seriously.
How can you tell that in an interview? Well, unfortunately, its very hard to tell. Being with a company large enough to support that kind of infrastructure helps, but it isn't for everyone. If you like to be a free thinker, and forge your own path sticking it to the man then the small company world is great. :) However, with that comes less management and more coding.
Personally, I prefer having a dedicated manager. They're available when you need them. I remember having a senior developer as my manager at a small company. I could never get his attention when it was needed. Just rm -rf /'d a live site? Good luck getting advice on fixing that before the customer notices.
Target questions to ask:
- How is work assigned, and are tasks defined in specifications or requirements?
- How are the development teams structured?
- Is there upward mobility within the company?
Once you know how the team functions, you'll know if the manager is on the ground fighting kernel panics or not. When you know the structure of a single team, you'll know where you fit in. If there's no leader within the team, you have a problem. Knowing about advancement tells you whether or not the company is interested in hierarchal management. If they aren't, well, management is likely just a title on their desk.