We don't have paid or even official team leaders, but if our team has one, I'm pretty sure I'm it.

First of all, it's good that you know your team members' strengths and weaknesses. You will definitely be able to steer things better w/ that info. Since you are organized, I'd probably keep a record of who's doing what or what was decided when decisions are made. One of the most important things is to be able to manage the time available. You'll want to get input from the others (without the one who likes to talk things out going on and on too long) and after some ideas have been presented, say, "So what I'm hearing is that we have options A, B, C with these pros and cons(briefly summarize). Does anyone have any strong opinions on any of these?" Then take a vote or make the final decision having all of the needed info.
I've found it's very important to be an effective communicator, making sure all members of the team know what's going on when, and what was decided. Email makes this very easy, esp. if you don't have a common planning time. Also, you'll need to be the go-between for your team with the principal.
Personally, I don't like being told what to do, since I am an experienced and trained professional, too , but I appreciate it when someone takes charge and leads in a well planned manner. I can't stand it when people are wishy washy. Open minded, yes. Indecisive, no.
Good luck!
