If you have no clue where to start, then you need to define your skillsets
and research your options thoroughly before any commitment. And by
commitment, I mean that, because it is a competitive environment. Here are
some options off the top of my head:

- Affiliate programs
- Freelance (writing, art, programming, translating, transcribing)
- Ecommerce (be your own storefront)
- Whitelabel - Make your own brand while someone else does the work
- Marketing - SEO, PPC, SMO, others

Besides from Freelance, which can be started today (like elance.com),
everything else will take some investment of time and energy/money before you
will see any return. Research the options, feel free to ask questions, and
think about what may suit you and your personal situation the best.

Just my 2 cents =D

This is an old question I realize it, but people are still searching for the
same types of answers. People can and do make money online but like gjh said,
it isn't easy, or quick. One of my favorite ways is writing, either online at
sites like Squidoo or on your own blog. You can earn revenue from advertising
or products you sell through product reviews and such. Other people like to
sell products on Amazon; getting products from dropshippers and letting
Amazon handle the orders and processing. There are countless ways, but they
all require the same thing.... YOUR hard work. None of the paths are easy, or
quick.

See this thread for some more thoughts and suggestions

I do not wish to discourage you, because it certainly is possible, very possible to earn money and work from home.    I know because that is what I do...But...Let me tell you that it isn't as simple as it can be made to sound.  Buy this, buy that...Make thousands....in your first month!!   I worked at this non stop for months, studies marketing, studies web design...There is a bit to it when you do it on your own.    If you are really keen to find out a little more contact me directly as I am not sure what I can state or not state with the rules here etc. 

Affiliate marketing is really good online money making. If you have blog, you can put Google Adsense is also good online money making.