Are you all in one office? If so: put the radio on. Makes it much easier to turn round and start a random conversation when you're not breaking a silence by doing so.
EDIT: Now I'm back from briefing, some more in-depth bits. I only went from tech to manager a couple of years back so not long been through the learning curve as well.
Trust your technicians; give them projects and trust their answers. You might need to coax them through a project in the early stages but once people get used to the responsibility, you'd be amazed what they can achieve. Have a little belief.
Be constructive, not just critical: if someone's done something wrong, or in a way you don't like, don't get angry, just point out how you'd do it and why. A lot of the time it's just pointing out how their actions might appear to others; as a manager you have to be more aware of public perception of you and yours, and those lower down might not necessarily be aware of it.
And tying into that public perception, as @alan-d said - back your team in public. Be on their side. Make what polite excuses you have to to other staff and then have quiet (and constructive) words in private.
Be firm but fair
Treat each individual appropriate to their personality and ability
Publicly protect your team - if issues crop up deal with them behind closed doors wherever possible
If you make a mistake - admit it.
Don't be afraid to ask for advice either from your team or anyone else.
Don't micro-manage - Let the team do their stuff, check progress occasionally if required but don't sit on their shoulders!
There are many more do's and don'ts most of which are common sense and you will find them out as you gain experience, if in doubt think back to a manager you worked for in the past and think 'how would they have handled this and did it work?'
All I would add to all of this is that, at the end of the day, it's not a democracy. You're going to be held responsible for the dept, so you'll be making the decisions. End of.