Raj,
While you're still at the planning stage, it might be a good idea to see if you can get a professional carpet cleaner somewhere outside of the area you plan to work in to take you out for a few days and give you some insight into what it is like to be a professional carpet cleaner, you may love it, you may hate it, either way, it's worth the time to find that out before you spend money on machines, equipment and commit to all the advertising you'll need.
Simon