Please don't be discouraged. I write for Suite101 and also some of my own blogs. In my experience you don't see any real money coming in until you have at least 50 posts. A few tips?
Do keyword searches on Google AdWords to see if the subject you want to write about is being searched a lot. For example, "promote my website online" only gets about 28 searches per month, yet "marketing online" gets more than half a million.
Promo like the devil! I added Shareaholic to my Firefox toolbar and every time I write an article I promo it to Twitter, Facebook, Stumbleupon, Reddit, Yahoo Buzz, Digg, Google Buzz, and a few others.
Stick with it and you will see results.