You start by developing a business plan.
http://www.sba.gov/ and
SCORE "Counselors to America's Small Business" | SCORE are great places for learning how to develop your business plan. We could also help you develop your business plan on this site.
By asking about prices, are you meaning what you would charge to provide certain services in your hair salon?
How many chairs for customers will you have in your salon?
Where is your salon to be located? In your home or out of a shop somewhere else? Those are just some questions to initially ask yourself when developing your business plan and knowing how to start your business.
There are also links to questions about hair salons on the bottom of this page. You might want to click on them to see what the answers have been.