A quick list of resources - courtesy USISTEF
A better way to think of your business model - the Osterwalder method (on HBR)
Registering a Business in India
Business Data and Market Intelligence (DIY)
2 second response from me:
Use census.gov's tools: http://www.census.gov/data/data-tools/cbb.html
3 min read + 2 min video
In graduate school, one of the things I learned about giving presentations was to "know your audience".
This is very relevant to know as you can adjust your story and the presentation style to match the needs of high school students or undergraduate sophomores or a room full of post docs | professors | subject matter experts.
I learned to apply the same principle when it came to selling products or services. Know your audience, translates to "know your customers, potential customers". Where students and scholars look for knowledge alone, customers might look for knowledge and a product, or just the product, or just the knowledge alone.
In any case, it is crucial for you to know who your market segment is and how they are spread out through geographical or other territory.
A great way to find a lot of such information is through maps. If I wanted to look at age groups, then I look at US Census data (new window).