I came across Quora.com. This site is simply doing its job of answering questions. You have a question on any topic, just fire it up there in the right feed category and people will try to answer that. You get opinions and references for your any question on the subject.
I explored Google Analytics, Google Adwords and now going to explore Google AdSense. I did not master any of these but it has been a wonderful experience so far.
August 18th my course "Java Interview Guide" went live on Udemy. And since then I am busy promoting it. It is around a month now and all that I have is $18 earned so far. However, in trying to market my course I have learnt many other things that I would not learn being just a programmer. Words like SEO and Marketing are buzzing in my ears now. :P