Your task as an affiliate is to help your visitor decide what to buy.
One successful technique is to gradually lead your visitor towards a purchase. Start by outlining a problem, discuss a good solution that has worked for you, and end the article with a link that is a call to action, such as a hyperlink that says, "Find out more here."
Your task as an affiliate is NOT to sell (that's the merchant's job) but to presell, to warm up your visitors. You want your visitors in a ready-to-buy frame of mind when they arrive at the merchant's site.
For superb advice on preselling, I strongly recommend you join Ken Evoy's 5 Pillar Affiliate Program. It's free to join.
Next step : Place adsense ads on your site