Winnifred, I see others here have given you a lot of good advice. However, I didn't see anyone mention this one very important thing which is, "don't put all your eggs in one basket.". For example, don't let Google AdSense be your only source of income. Many people have been hit with Google's constant algorithm changes and they were wiped out.
As BigJ said, there are many different things that you can do to make money online. Choose the things you enjoy and go for it.
I understand the basket part, but could you explain further on how a site gets wiped out? Is it because articles that have been uploaded so far have been strategically geared towards the previous version, and with a new one has become unsearchable and obsolete?