Running a blog is a great way to make money while working from home in your pajamas (or is that just me?). But you can’t set up your site and expect the money to start flowing. It just doesn’t work that way.
You need to first make sure you have started a blog and that it is set up the right way. If you are just getting started, check out the Start a Blog series.
Bloggers make money in several ways. While the most popular method is through an ad network, that is only one way to make an income from your site. There are many options available and it is wise to investigate and be willing to test them all.