Freelance work is when you work directly with a client to produce a website and they pay you directly. You often have to find the client and bid on the project they offer.
It may be smart to build an LLC or Corporation before taking on freelance work. Consult a tax specialist or an internet resource to determine what you should do with your freelance earnings to reduce your tax liability. You may have to pay 40% tax on your earnings if you do not plan correctly.
There are a number of sites online designed to help developers find freelance work. One of the most popular is Freelancer.com
We suggest you also use Craigslist to find projects you can bid on. It can also be a good idea to find a web designer you can work with on projects. If you can combine your skills you may be able to bid for larger projects.