Track current trends - What stuff is in the media right now? It's good to pick a topic with longevity (you don't want something that will fall out of fashion), but if you can piggy-back on a trend early on, you can quickly establish yourself as an expert on it before anyone else. Searching #journorequest on Twitter shows what kind of people/topics journalists are currently reporting on
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.