Online courses are perfect for those people that have a busy life. They are convenient and they tend to be cheaper than an actual class. But i have heard that if you pursue an online degree it is not as valuable as a regular degree.
Also it depends what courses you take online. If you take a liberal arts class like creative writing, or history etc..., than it is not bad. They are quite easy to follow and do well. The problem is with science courses, they tend to be very hard. If there is something you dont understand you wont be able to stop the professor and ask a question. The grading system is different too. Since you are at home doing your HW and tests, than they tend to be much longer and harder.
This website, CareerInfo411.com, has some good information. Take a look, maybe you will find something helpful.
Best of luck