Creating a blog is the best and easiest way to start affiliate marketing. It is also one of the best platforms for affiliates because you can increase your affiliate sales as much as you want.
Moreover, you can even start a WordPress website to start making good money from affiliate marketing.
You need two things to create a blog or start a website. First is a domain and second is the hosting. For domain, I recommend GoDaddy, where you can grab a domain as low as $9 (grab at $0.99 for new users). Now for hosting, there are tons of providers available in the market. My recommendation is Bluehost which starts at $2.75 a month only.
After that, you just have to install WordPress CMS to your hosting (most of the hosting provides one-click install).
Voila! You have successfully set up your website. Now just publish quality content related to your niche and grab a good amount of traffic by ranking your website on search engines like Google, Bing, Yahoo, etc. [See: Complete SEO Guide to Promote Your Website and the WordPress SEO Guide].
Create a review article where you can put your affiliate link, and when someone purchases that product using your affiliate link, you will receive a commission.