A wonderful question! I asked a financial planner running two businesses that same question. His response, "The 4-Hour Workweek by Timothy Ferriss."
The book is full of useful and useless information. Take away only things that apply to your business. A few suggestions are priceless for managing time. My favorite was email and telephone requests.
I was working 60 plus hours a week at my day job. Being a parent and starting a business was daunting. Following The 4-Hour Workweek suggestion, I set scheduled times for email and telephone requests. Thus freeing enough time to get work completed. This also allowed me to leave work on time. Giving me time for family and the new business.
I also learned families need structure. My children were four and six at the time. I started doing homework with them as I made dinner. This change accomplished two things at once. I also began to write and draw while the kids did homework. A few small interruptions during math is more managable than play time arguements.
Create a kid work station in your office. I'd rather work with my kids than the person my old boss stuck me with. Work through kid noise and some great memories can be made.