Almost everyone has a particular set of skills that they could share with others, and the internet gives them the perfect medium to do it. Online training courses are big business.
So what talent or skill do you have that other people might like to know about? You might be surprised by the amount of knowledge you’ve acquired in certain areas when you stop to think about it. No matter what it might be, there is probably a market for it.
Some sites where you can sell courses include Lynda.com, Academy of Mine, and Digital Chalk. You might also consider delivering your course via Youtube, or on video from your own personal site.
The only caveat is that you need to know the subject and field well. People want to take courses from someone who can provide them with information and tips they can’t find elsewhere.