This collection of 250 ideas - researched and published by the Ugandan Investment Authority (and published here with their permission) is an incredibly useful resource to help more of us in figuring out what we are really interested in and read enough about it to give us a sense if it fits our talent and passion (and if it makes financial sense)
This is not so much a course as a collection of businesses you can consider and then enough information to give you a better sense if you wish to pursue it. From how much it costs to the kind of resources needed, how much time and potential revenue. Keep in mind it is based on Uganda so you'll have to research the specifics for your own location, but at least you'll have a much better sense of what to look for and gut feeling for the numbers and possibilities.