Wow, am I ever late to this convo -
I personally am on Elance as "JamestheJust" and have made a good part-time income (working full time during the day and staying up like a vampire).
I'm now 100% on Elance, with a dozen or so websites in AdSense as well as affiliate product sales (average about $400 a month).
My advice is to learn how to create a website (WordPress is incredibly user-friendly), and use it for affiliate product sales.
Writing a review per product per page is a great way to close sales, and has worked great for me (when I actually get the time!).
I've Hubbed about freelance writing, too, and my website http://theaveragegenius.net has a couple of posts on getting work on Elance.
I'd recommend Elance over the others since they have a $50 minimum on jobs - it's amazing how many internet marketers (like me, though I don't do this-->) try to take advantage of writers with $1-$3 articles.
Um...no. Sorry. Not me...anyway: fully recommend them, or oDesk, Guru, Demand Studios...HubPages is a great way to make money, too...though I haven't yet here :)
Best of luck - although you asked the question over a year ago.