Advertising is easy to start, making it a popular income stream for many bloggers. However, it’s not nearly as lucrative as it once was and it requires a lot of traffic to be truly profitable. Also, it runs the risk of frustrating your readers (ever been on a site only to be assaulted by the ads?) and making your site look cheap and unsophisticated. Therefore, it’s not a top recommendation of mine.
The easiest PPC method to get started with is Google AdSense. However, in order to make any kind of decent money with display ads, you’ll need quite a bit of traffic. And by the time you get that much traffic, you’ll make more money going with an ad management company like Mediavine (minimum of 25,000 monthly impressions) or AdThrive (minimum of 100,000 monthly pageviews).
Once you setup your account on AdSense you will be given a code to add to your blog. This code will automatically display advertisements on your blog from companies who are part of Google’s advertising network. You may see ads from small companies related to your topic, or you may see ads from large companies that are completely unrelated to your topic.