Selling via links in blog posts – Can you do this?

Im wondering, as a new (ish) boy if I can post in my blog about a subject, product or service that I can earn from when visitors click through and buy or as lead generation etc.
I have seen people post about using Amazon affiliate to do something like this but im a little unsure of how it works.
Any help will be good thanks

See original post by UrbanColour