Sounds like you need to hire an accountant especially if you are going to own your own business. There are ALOT of rules regarding taxes for businesses and if you don't have the know how you need to hire people that do. You will need to pay taxes for payroll, quarterly taxes, monthly expenses.
Before you open the doors I suggest you attend one of the IRS Small Business Workshops. The IRS isn't that big bad guy they are there to help you and get you the answers you need.
I would start here -most of these are FREE and very informative. There are 2 or 3 you really should take before opening the doors then contact a CPA to help you determine your estimated taxes. Well worth the financial investment and it's a business tax deductions as well.
Small Business Tax Workshops and Webinars
This is a workshop I would recommend for anyone starting a business. they let you know exactly what tax forms you need to fill out and maybe some forms that are specific to your state.