Although I've only been in this business a fairly short time, I cannot underestimate the importance of networking. I cannot tell you how many jobs I have gotten and how much advice, story ideas and education I've gotten through networking--it's invaluable. I got my first publisher because of networking, and although I had to back out of it, I wouldn't have gotten there in the first place without knowing someone there. I have heard several stories of authors getting published because they were in the right place at the right time. There is so much competition out there, sometimes just knowing the right person is what you need to get your foot in the door.
There are many different ways to network. The old school way is to join writers' guilds and associations and attend meetings and conventions. A more modern way is to meet people over the internet. I belong to several writing-focused discussion boards (and horse-focused ones) and an email list of equine journalists. This is how I met my mentors and obtained a large amount of work, either by helping them with their workload or following their advice to try sites like oDesk.
I highly recommend you meet and talk to as many writers as you can. Tell everyone you know that you are a writer and try to work in the type of writing you do in conversations--you never know when some work might come your way because of it.