As an aspiring or serious writer, where do you think you will get the bulk of your work from? The Internet? Job auction sites? Let's think about these options and how well you can realistically make money from them.
The Internet seems like a great place to start - lots of opportunity and unfortunatly lots of competition. I signed up with two writing sites when I started, and ended up paying around $100 for subscriptions to sites which promised the best ever writing jobs. They were making crazy claims such as 'Make $300 a day easily writing blog posts'. The reality is that there are literally MILLIONS of people who have already joined these, and your chance of getting work is very slim. Infact, I am willing to bet you won't even recover your subscription fee.
Job auction sites also seem like a good idea because you can attach samples of your work and really show off your experience. The truth is, most people end up undercutting one another on the bids and the job is usually awarded to the lowest bidder. Highly paid jobs are given to more experienced writers. Don't get me wrong through - you CAN get work here, and I recommend using Elance and ODesk as well as Guru.com. Forget the other sites, there are far too many low paid writers bidding on projects which are likely to be picked up by a low paid writer.
Your best bet is to work at a local level. Join your local chamber of Commerce and advertise in their directory. My own town has literally zero competition, and I have just been hired by a school to write their reports and their newsletters. And guess what? They are paying for out of pocket expenses such as petrol and babysitting, and the money is quite good.
As a writer, you need to keep your options open, and while the Internet can present some good options, you should really build your reputation locally - this way you will have steady work coming in for years to come.