Let me give you some of my thoughts.
"A business is a cycle, where a products or a services is sold, in an attempt to make profit "
This profit (Money) will be spend somewhere generating a sale for other.
I think, now you must have started visualizing things :)
let's move on.
Now, choosing a product.
First choose few products, which are used daily and their consumption cycle is from a week to a month - hope you understand what I am try to say.
choose services Example: selling a software. (Which can be sold to n numbers of users)
reselling cheap duplicate.
repacking in attractive way and selling.
selling website source code
Don't forget that you also have to be updated about people mood and factors influenicing it eg: TV Ads, Internet Ads, Celebrity endorsement
Also, keep a price watch - cheap, cheapest, popular and recently launched.
ALSO, business is
- Making things easier for others > eBay > made buying/selling easier
- making things faster > All booking sites.
- making things useful for others > groupon
- making people updated > news websites
- you can start adding your own. :)