That's good site, But Questions there, are so difficult . I had created account and given answer only to 1 question which was related to web server Because I don't know much about telecommunication .
Free Lancing ,as you asked , is the best way to work online and It even yields highest than any other method. Last Night I have got 50$ only by half hour work.
There are many platforms where Buyers describe their projects and freelancers Put Bids on them .. Then Buyers chooses 1 Service Provider (Freelancer) to work on his project...
some sites are

http://getafreelancer.com
http://oDesk.com
http://php-freelancers.com


One thing I want to clear is that some people think that Freelancing is only for Programmer ,
But You can see in the sites above that there are many categories even DATA ENTRY for a Naive Computer user
;

Just Give a try , It's somehow hard to get your first project , But after 1 project buyer will give you 'rating' , which increase your chances to be chose for next project


Best of Luck