As someone who's been immersed in a number of online industries for quite some time, I know a thing or two about what it takes to succeed in this arena. However, just like you, I started at ground zero with little knowledge, but a great deal of passion. What I learned along the way were some invaluable lessons from failure that hurt at the time, but helped immensely in the grand scheme of things.
21. Facebook – Facebook swap shops are great for selling things locally. It’s like CraigsList, but a little easier. You simply search for swap shops in your area and ask to join the group. Once you’re in, take a picture of the item, write a quick description with the price and post it. It doesn’t get much easier than that. You can generally expect to get about what you would get at a yard sale, maybe a little more.
You can sell your ebooks through Amazon's Kindle program or Apple's iTunes Connect, which gives you access to a large majority of the digital-book reading market and the barriers for entry are incredibly low. You don't need to invest lots of money to make this happen, but you do need to invest lots of time, not only in writing the ebooks, but in marketing them as well.
How much will you make? I think my best month with Google AdSense was almost $5,000 over the last ten years. That amazing month blew my mind since it was actually near the beginning of my blogging journey. When you go from making zero to $5,000 in a month, that will rock your world. For me, it also got me even more excited because I knew there were other ways to monetize.