While you can try to go through someone like Amazon to do this, I like what Lina Scheynius has done. She uses PayPal for the collection of money, which doesn’t surprise me. What she also does is create YouTube videos like this
That way you can see what the book looks like before you buy it. Smart! And given that she has sold out a number of her books, it’s very smart indeed.
Obviously you need to have great content, and she does. Once you have that, capitalize on existing tools to take care of all the boring essential part of making it easy for people to buy what you made.