One of the most important aspects of leading a group class project is making it clear to all involved that everyone at the table has a voice in the project. While there will always be one or two individuals who are more active than others, the leader has to keep these more outspoken members of the team from totally drowning out the others. One reason for doing this is that it is only fair, and the other is that the quiet guy off in the corner may be a genius your group needs to hear.
When conflicts occur over either the direction of the project or small details (as they inevitably will), it is the job of the leader of the group to keep this from become personal or disruptive. At the same time, conflict can often be used to generate good ideas. The key is finding the right balance so as to keep things humming along.
As the leader, avoid the trap of carry the biggest part of the load. Make sure you delegate tasks to each member of the team to distribute the workload fairly. This does not mean shifting the workload to anyone who is handy. You should instead work to the strengths of the group, using their collective skills and knowledge to best advantage.
Another vital skill for a leader of a group project is time management. Since school projects usually have a deadline, you have to make sure that all parts of the project are proceeding at a pace that will meet that deadline. To do this, you have to keep lines of communications open so you will know if someone is falling behind. If they are, you will either have to find a way to motivate them to greater effort, help them resolve the difficulty slowing them or assign someone else to help them.