I have recently changed my website Markspixel.com a bit to make it more focused on code than design which is what I used to do a lot. So now to get started I decided to add some affiliate products from codecanyon for example to compliment my inventory since I don't have much time at the moment to make my own themes, scripts, etc. I figured it might be a good thing to keep doing. What I do for affiliate products is that I make a buy now button that is an external link to the page where a user can buy the product.