SpicyDirt pretty much nailed it, so I'm not going to waste your time with the same material. However, I did want to throw an exaggeration on number one and five. If you do not have one and five, forget the rest.
As a leader, you're in control and you set an example for the group. If you truly want the group to live and thrive, you have to be active. You need to show you care and have a definite dedication to the group. If members feel like you are not committed, it'll rub right off on them and you'll most likely lose majority interest in your group.
Stick with it. Times are going to be tough, especially as a leader in your group. But if you're truly passionate about the group and want it to succeed, you'll find a way to make it work. I'm telling you from personal experience that running a group is not easy, it is very demanding, and you're going to be pushed to your limits. Don't let it discourage you, just keep going. I've gone through a lot with my group, I've been up high and down low. There was times I wondered if it was even worth it and you're probably going to go through the same thing at one point, but do not give up.
Lastly, I'd like to be frank with you. Take your time when deciding whether you want to start a group. Ask yourself questions. Why do I want to start a group? Am I capable of running a group? What are my goals for the group? Do I have the time to run a group? If you can answer questions like those and you still think you want to run a group, I say go for it.