I believe you need to do some homework before you launch into a business. You are asking some basic questions and to get an couple of answers here may not be in your best interest. When someone sets up a business there is a hugh time investment and a monetary investment of some sort.
You need to first develop a business paln. i.e. Exactly what does your business provide? What is the competion for this business? What ROI am a looking for? And the list goes on.
I suggest you do that first, then come back with more definitive questions.