If writing books interests you, an option you have is to self-publish eBooks and paperbacks with Kindle Direct Publishing, and reach millions of readers on Amazon. Publishing takes less than 5 minutes and your book appears on Kindle stores worldwide within 24-48 hours. One can earn up to 70 percent royalty on sales to customers in the US, Canada, UK, Germany, India, France, Italy, Spain, Japan, Brazil, Mexico, Australia, and so on. One can keep control of one's rights and set their own list prices and also make changes to one's books at any time. BooksFundr and Pblishing.com are two other places to get your book published and earn money.
One of the cool things about Google AdSense is that it's so easy to get set up. If you have a blog or website, you can sign up for a free Google AdSense Account. From there, Google will give you a unique code that you will paste onto your website. Google takes it from there, tracking your page views, traffic, and earnings on your behalf. There is no upkeep or maintenance to get this thing going, which makes it a no-brainer if you have a website already.