According to wikipedia:
freelance is somebody who is self-employed and is not committed to a particular employer long term
The companies now are most probably outsourcing their projects. So freelancing is becoming more popular these days. A freelancer has also benefit of working independently and getting extra income by doing some hour of work.
I suggest you if you want to become freelancer then you should be more specific to one field. There are lot of skills to cover i.e designing, programming, writing, marketing and in which there is its own categories. So e.g. if you are in programming then don’t go for all the popular languages. If you become more specific to one language or one tool then most probably you get more work on internet and ultimately more income.
If you are new freelancer then you have to choose small projects and little budget. As there are many other freelancers in this field so if you bid as low then you should win the bid and also you will get portfolio in the beginning. You can put your first project in your portfolio.
Next thing is that don’t try to get so many projects at the same time. Get as many projects as you can handle easily. For example for newbie one project at a time is good.
Now let me share you some of the popular freelancer sites from where you can get projects. In these sites you first have to signup. In some websites like elance.com you have to pass test in order to bid for any project. And in case of odesk.com , if you pass the test then you can have place more bids. Here are few freelancer sites:-