If you are looking for a way to monetize your website, then Google AdSense is the place to start. Google AdSense is the most popular Pay-Per-Click network. Google AdSense is based on Google AdWords. AdSense and AdWords are like the Yin and Yang of website monetization.
AdWords lets you buy advertisement that is placed on Google search pages as well as Google's network of AdSense users. So the ads that you put on your website, by joining Google Adsense are actually the ads people pay for through Google AdWords. Google makes a profit and so do the websites on which the ads are places.
With Google AdSense you paste code on your web page which will then display that are relevant to the content on the page. So, if your web page is about cooking, all the ads that appear will be about cooking, food and recipes.
This video explains how to start working in Adsense. It explains how to customize your ads and embed them on your site.