If you have a contract with the state to receive payment from them for children in your care then I will tell you the mistakes I made. In my center that I owned I spent some money on Newspaper ads, did a tiny amount of radio ads and not one person ever responded to them.
The people who use the state to pay part or all of their child care expenses can't afford those luxuries. If you have that contract then just make sure that the state office where women go to sign up for childcare assistance has your home on their list of approved care providers.
If you are going to rely on people to pay you out of their pockets for your care then be prepared to have long periods of time between parents seeking to do full payments. It seems like to me that nearly everyone I ever had come to my center qualified for some assistance. I think out of all my kids I only had 1 child that paid cash out of pocket and they could only afford 1-2 days a week for a period of about 4-5 months.
Do the bank account, keeping the funds separate makes it very easy for your CPA to see how much of your house payment, utilities, wear and tear on your property, home insurance, etc...can be a deduction. It also makes it easy to keep track of just how much money is going out and you can track it to see what areas you want to add more to or cut back. You can also leave a majority of it in the account and pay yourself a salary so you can do regular tax payments.
Get personal liability insurance. I carried mine through our car and homeowner insurance agency. No one ever sued me but if they had I would not have lost anything personal.
Look for a supprt group(?) for home care providers in your area. I was active in our local Directors group and I took classes all the time that helped add up to fulfill my 20 hours per year required of training to keep my license. I learned most of the financial aspects of the business from those classes. It also gives you a group of friends to call on if you are sick and need to know who to hire to substitute for you. Everyone needs a day off every now and then if even only for that wonderful yearly OB/GYN appointment we all love.
There are food programs out there where you can sign a contract and go by their guidelines and get reimbursement on your groceries. Such as buying only 100% juices, fresh fruit and fresh veggies, etc...the one I know of was called Little Dixie and is in Oklahoma. There must be something in your state too. Again the support group would have some of this information.
http://www.littledixie.org/ldcaaCACFP.html
Good luck having a fulfilling career and a lifelong joy.