Earning money on the internet is a nice thought. You can work from home, you can fit work to your own schedule, etc. etc. The problem is that many people online today seek what is referred to in the internet business as instant gratification. In other words, they look for a quick score, and when they do not find that, they give up and figure they failed. There is an important fact we should clear up right away: earning money on the internet is not always easy. I do not say that it isn't easy, because sometimes it is, if you are "in the right place at the right time," but often times it is hard work, just like any other entrepreneurial endeavor. There are a lot of places one can start, and a lot of those places lead to dead ends. The most important thing is that you do not give up right off the bat—do not let yourself be discourage because you failed once.
As almost every successful business person will tell you, success requires failure. You have to learn from your mistakes, adjust your methods and tactics, and move on with the lessons you learned guiding your future actions. In this way you always get better. Say your first endeavor ends up with a loss of $100. You might get discouraged and quit right there. Then you absolutely solidify your failure. Instead, try thinking of what you did that caused you to lose money, and give it a second try. This time, you might lose only $50. Hey, that's better than last time! And if you keep it up, you will only have to try another three projects to be completely even.
But the truth is the math is even better than it seems in the above example. Why? Because it is not only when you fail that you learn. You also learn by winning, or succeeding. That means that if you are conscious of what you are doing and are able to objectively analyze your work, you can improve every single time. The end result is that you won't keep moving up in fifty dollar quantities, as is implied in the example above. You will start to increase your profitability by more and more each time. It's sort of like compounding interest… every bit of experience you have is profitable, even if the initial action was not.
Where do people get started? This is a common question, and rightfully so. This internet, as it is, is a huge place and it can be very hard to find out where to begin. The best place, from my experience, is in forums / message boards. These are communities of people who discuss various topics and share insights, ideas, and criticism. You can find forums specific to your industry or specialty, and if you read as much as you can, you can gain experience without even spending any money, and then you can get a pretty good idea of where you should start. One easy rule for those who are having a hard time getting started is just to look at what others are doing, and try to mimic it while adding your own twists. As you progress, you will learn, and as you learn, your endeavors will become more profitable.

To hear a personal success story, check out the authors' page on how to earn extra money online.