First thing to do is write a plan. What is your main goal? What do you enjoy doing? Pick something that will motivate you. For me writing has always been fun and gardening has been a hobby. It wasn't hard to combine the two. I found a few places to submit articles for publication like Yahoo Voices. Once Yahoo Voices accepts your article it is published to the web. Payment is based on the number of readers you attract so marketing your own work is important.
Joining an on-line survey site is a good way to make money also. Survey Head is one of my favorites. In addition to cash rewards (paid through pay pal) I've also received products to test market. Since saving money and trying free products is another of my affections this is a double tribute. I recently completed a survey inviting me to join a consumer panel for a large distribution company that will provide trial products and compensation.
I am a big fan of e-bay also. It's not hard to find those unused items hiding in the closet that you won't miss. First rule of listing on e-bay is always check the amount of money your item is currently listed for. The number one way to forgo a sale is to overprice your item. Communication and quick responses are also important. You will be your own customer service department. Once your items sells ship it promptly and you will always have a returning customer.
If you prefer something more contemporary ways to make money check these two sites, http://www.workathomecareers.com/ and http://www.wahm.com/. Both have legitimate work at home opportunities and great advice for finding the right fit for you. Be very cautious though. If it sounds too good to be true it more than likely is. I recently completed an application and was invited to a web conference. I immediately realized I was put in the middle of a marketing scheme. If I wanted to market this companies products, which are outrageously priced, I had to purchase an annual membership and spend a minimum on there products every month. Never pay any one for an opportunity to make money!
If you have any further questions, or wish to add your own comments please feel free to contact me.