I started my own business back in January. Before you do anything else, write a business plan and stick it in a drawer for a week. Read some of the magazines geared toward small businesses (Entrepreneur, Business 2.0, there are others shelved nearby at Borders or Barnes & Noble). Pull out the business plan and revise it.

The business plan is your way of conveying some critical information to the people around you and will help you clarify the idea for yourself. You don't need to go into details like the color of ink on your business cards, but make sure that you have some sort of schedule for income and expenses. Careful planning will save you headaches down the line. By headaches, I mean things like bankruptcy.

You absolutely must incorporate as a business. It'll cost about $500 to have a good lawyer help you do it. You'll enjoy all the legal protection the government has to offer for businesses, including protecting your personal credit and assets.