Haven't been a while here, too.
All I have to say is.... /PANIC! Since my senior project planning class* has 3 people (one of them was late), I've been selected to be be our Project Lead and our Development Lead. I'm not used to so much authority.. Sure I had a WoW Guild but, for the most part I just let people do whatever since I was laid back.
Too much pressure... AAAAAHHH!!!!
Mustrum, Aeson I know you two do big projects and stuff with real life consequences, do you have any pointers?
You know wrong.
I am also more the laid back type. Take it from Picard - listen to the others and than decide the approach.
Figure out where you (or the class teacher or whatever) wants to go with your project, and how you want to do it.
Decide on teams, on iteration steps you take (these steps might include figuring out where you want to go next or if you are still going the expected route or the destination has changed.)
Try to estimate how long individual tasks get (which should first be done by those that are planning to do). They will be off. You will be off. That's okay. Compare expectation and reality, and use that to improve your estimates.
It is important to organize tasks in smaller chunks. The more complex a task is, the worse it will be defined, the harder it will be to achieve it, and the higher will be the difference between expectation and reality. (Hint: Any task usually take longer than expected, not shorter.)
Organize your teams discussions. Either moderate them yourself or set someone to moderate them. Only one persons should speak at a time, and if two people want to speak at the same time, figure out the order in which they get to speak. (By the way: I think it's a good thing when you need to do this often - it's a sign for motivation). If no one has to say anything, you need to bring up questions.
In software development, having two people (pair programming, extreme programming) work on one task has shown good results. I don't think that is limited to software development. You need someone to bounce ideas off, someone that questions your approach or someone that helps you when you are stuck. But if the team is too large, you will quickly run in circles and not achieve anything (especially without a moderator).
Another technique are short (typically daily) meetings (typically done standing) where everyone quickly presents what he did (and any issues that still need resolving) and what he will do until the next meeting.
Generally it's good to have a good "feedback loop". Regularly giving feedback enables people to see if they are still on track and allows you to correct mistakes and address. But at the same time - don't let it become "micro-management". Trust that people do their job and don't move your targets around.