Running your own business is supposed to give you flexibility, but not when it's a start-up. It will chew up every minute. Whatever else your company makes, you can be sure that it will manufacture guilt at a steady rate. So warn your spouse and kids: You won't be around as much. "Get your family together and ask them what they think about your plan," says Tom Gegax, consultant and co-author of "The Big Book of Small Business." "When the clock starts ticking, the stress can be paralyzing. You'll need them to understand."