So, you've got a great group of musicians together, but your band isn't going to run itself. When you start moving out of the practice space and into the big, brave world of the music biz - live shows, music for sale, all that jazz - then your band needs some kind of organizational structure, especially if you don't have a manager on board.
Why, you ask? Well, for starters, it gets pretty confusing when your drummer and your guitarist are out booking shows for the same night. It's also confusing when someone wants to talk to your band about an opportunity and they don't know how to contact. Don't worry, getting your band running like clockwork doesn't have to be hard. Visit Bands 101 for more info.