Find a profitable niche. Starting with your interests, write down as many niche ideas as you can. Think about topics people might search online. Ideas include passions (like surfing or body building), fears (like spiders or speaking in front of crowds) and problems (like getting out of debt). Do keyword research to see it others are interested in the topic. Find out if a domain name is available that matches the keyword 100 percent. 
There are numerous repositories to source affiliate products and services from. However, some of the biggest are sites like Clickbank, Commission Junction, LinkShare and JVZoo. You'll need to go through an application process, for the most part, to get approved to sell certain products, services or digital information products. Once approved, be prepared to hustle.
Thanks for the very, very in-depth article. I am a real estate agent in Miami, Florida and have been blogging all-original content for the past 21 months on my website and watched traffic increase over time. I have been trying to grow my readership/leads/clients exponentially and have always heard about standard SEO backlink techniques and writing for my reader, not influencers. Recently, I have had a few of my articles picked up and backlinked by 2 of the largest real estate blogs in the country, which skyrocketed visits to my site. Realizing what I wrote about, that appealed to them, and now reading your article, I am going to continue writing in a way that will leverage those influencers to help me with quality backlinks.