If you are more confident in your skills, you can also market directly to websites and blogs. You can contact the sites by email to market your services. That will also enable you to select the specific types of sites that you are more comfortable working with. Since there are literally thousands of websites and blogs on the web, the potential market is limitless.
One of the cool things about Google AdSense is that it's so easy to get set up. If you have a blog or website, you can sign up for a free Google AdSense Account. From there, Google will give you a unique code that you will paste onto your website. Google takes it from there, tracking your page views, traffic, and earnings on your behalf. There is no upkeep or maintenance to get this thing going, which makes it a no-brainer if you have a website already.