Do you use twitter? If not, it might be worth looking into. I resisted at first, but have found that in some ways it is better for networking than facebook. (Although I must admit to liking facebook more.) On twitter you can find professionals that you might not normally have access to and link up with them. Plus, you can get the word out to a large number of people about what you are up to in your writing career.
That said, be nice too. It is considered “polite” to mix self-promotion with helpful advice, quotes and other fun stuff. And if someone follows you, it is always a good idea to thank them for it. Personally, I have my privacy settings on so that I have to accept someone who wants to follow me, but do what you are comfortable with.
The learning curve on twitter is a bit more steep than facebook in my opinion, but there is a help page that really does the job. Start there for the skinny on things such as finding people, following and direct messages. You don’t have to dive in and start tweeting away, but not having this social marketing site in your toolbag means you are one step behind as a writer. It’s worth a shot.
(And look me up! I’m catherinetully on twitter. Tell me you are a FZ reader so I know who you are…)