I think AdSense is a great way to make money online. It give me this great feeling when I get some clicks on the AdSense ads. If you follow the rules of Google there is no problem. If you violate the rules of Google you might lose your AdSense account. Below you can find the some Don'ts for using AdSense.
Never click on your own ads. Google can track where the clicks came from.
Never ask your friends or your family to click on your ads. You can refer them to Google AdSense.
Do not participate with AdSense for the money this is not a get rich quick scam. You have to put in some hard work to make the profits.
Be patient when you first start with AdSense. It doesn't matter if you do not understand all the aspects the first day, but be patient. It is very user-friendly program. Have fun.
It is very important to get traffic. Without enough traffic you can not make money with AdSense.