1. Ehow is a reputable and free site where you can share your knowledge with other members and make money. It is a slow process, but over time you can make a decent chunk of extra money. All you have to do is sign up for the writer's compensation program (WCP) and write 'How To' articles. These articles can be as simple as 'How to brush your teeth' to as complex as 'How to Build a Detached Garage'. I have been doing this sporadically for several months. I made about $17 in the first few months but I have less than 20 articles posted. The more articles you post and the more active you are in the Ehow community, then the more money you will make. Check out my other articles on Ehow.
2. Start your own website. You could sell products and services or just post information and make money from advertisements on your site. Sign up for Google Adsense and you can make money when visitors click on your ads. I created a free website on FreeWebs.com. There are many free web hosting services out there. You can do a Google search or even an Ehow search to find more free sites.
3. Start your own blog and use Google Adsense so you can make money when visitors click on your ads. You can write about anything you want. Check out the different blogging sites that I have listed on my personal website listed below in the Resources section. Check out Xomba in the resources section. It is a very popular blogging site so you should get a decent amount of traffic.
4. Sell items on Ebay. This is the most obvious choice, but there are so many opportunities to make money on Ebay. Find a niche that works for you or sell old stuff around the house.
5. Sign up for a seller account on Amazon.com. Sell your old college books and regular books on Amazon to make some extra money and get rid of some of the clutter in the house.
6. Sign up on DayTipper.com. This is a new site for me so I am still testing it out. I have posted one tip and it was approved. When it is published, I should receive a one-time $1 payment. This tip only took me 2 minutes to write. If you are creative, you could really make some quick cash.
7. Sign up on Epinions.com. You get paid to write your opinion about different things. I have signed up for this site and submitted one review. Reviews must be at least 200 words to qualify for income share. I will continue to test this site out and provide more information at a later time.
8. If you are artistic then sign up for CafePress.com. You can upload your artwork and set up a store. You can choose which items you would like to have your artwork printed on like t-shirts, hats, coffee mugs, etc. The website supplies all the products so you don't pay anything and you earn a very nice commission when your product sells. Ehow member AlmondSpecial was kind enough to share this in my comments section. Please check out her article about CafePress in the Resources section.
9. Etsy.com - This site allows you to buy or sell any handmade items. Check it out. You could sell homemade jewelry, clothing, t-shirts and more. I have not used this site, but it is reputable and has a broad range of opportunities.
10. Lulu.com - this site allows you to upload your digital creations. It can include photos, artwork, or even a manuscript. I have not tried this site, but it is reputable as well.
11. Sign up for Hubpages. You can write articles and receive money for Google Adsense, and also for signing up to be an affiliate for Amazon and eBay. You can really make some money here. See the links below for some great articles that were written on HubPages about earning extra money.
12. Find a legitimate work-at-home job to supplement your income. This can be anything from data entry to freelance computer programming. I have compiled an 8 page list of resources and information regarding this topic. Since it is too much to fit into this article, I have supplied the link 'Work-at-Home Jobs' under resources.