It's hard to say who needs you more: your kids or your company. Both rely on you for everything from morale to money. Unfortunately, says Dr. Joyce Brockhaus, a family and marital therapy specialist at the Family Firm Institute in St. Louis, business often comes first, and "entrepreneur parents really aren't there for their families." Following one major rule can ease the inevitable heartache: Articulate your values, whatever they might be, to your children.

If you say family comes first but never take a vacation with your kids, they'll smell a rat. If the company needs to be your top priority for a few months, or even years, brace the family for it and ask for their support. Luis Machuca, father of three and CEO of Kryptiq, a network security start-up in Beaverton, Oreg., says he tells his teenage sons and 11-year-old daughter "being their dad is a higher job than being a CEO, but being a CEO is a 24-7 job." He says they get it and they're proud of him; they even tolerate him taking speakerphone calls in the family car.

Frank discussions about work, while challenging, can inspire creative solutions to problems. Daphne Carmeli, CEO of a pricing optimization software company called Metreo, says she once felt pressure to be like the full-time mothers in affluent Palo Alto, Calif. But when she talked with her sons, now ages 11 and 9, about her heavy schedule, she realized that a) they were proud of her for "making her own work" but b) they were afraid to call her during the day. Carmeli has since developed an office culture that is explicitly open to kids. Telltale signs are a basketball hoop in the parking lot and a Ping-Pong net stretched across a boardroom table. Her sons come by at least once a week and have explicit permission to call anytime.

It isn't milk and cookies every day, but the positive upshot of having the kids around at work is that they really understand what their mother and her company do. Says Carmeli, "My little one says: 'I don't get why it's so hard -- you price more, you get more."