If you like to write, or think it would be fun to share your knowledge about a particular subject, start a blog. WordPress.org and Blogger.com offer free blogging platforms. You’ll need to pay a small amount (as little as $5 per month) to have your blog hosted. Try GoDaddy.com.

You probably won’t rake in dough right away, but you can once you attract an online audience. J. Money, who authors a blog called Budgets Are Sexy, says it took about six months before he started seeing any payoff. Now, he says, he gets a steady stream of income from advertising revenue generated by the blog -- enough to cover all his monthly bills and replace 80% of the salary of his previous full-time job.

Google AdSense is a popular (and free) program that lets bloggers display ads on their sites and earn money. You can also try so-called affiliate networks such as Commission Junction and FlexOffers, which allow bloggers to pull in revenue by promoting products and services.