Have you tried anything like this before? If not, a good starting point might be to seek out friends/contacts who have already had some success with similar ventures.
Thoughts that spring to mind (other than the above): find out what products people are willing to buy, set prices, find target clients, set up a website. Network like crazy. Dress up, go to parties put on your best smile, get chatting to people and hand out your business contact details - you can't beat word of mouth/recommendation for generating business.
Get a business package together and seek out people/organisations who might give you funding to start this off.