I write genre fiction. I made my first novel sale through an agent. I would recommend a two-pronged approach.
First, try to get an agent. (Through the accepted means of attending conferences, sending query letters, networking, etc etc etc.) Only consider reputable agents in this search, researched through the usual means for your genre. (Litfic counts as a genre for the purposes of this discussion.) (SFF has the Preditors and Editors website, frex.)
If you cannot get an agent, submit directly to whatever publishers will have you without an agent, through the usual channels. You lose nothing by this means, because if you do get an agent, you haven't already shopped the book to multiple publishers on your own. And if you don't get an agent without a sale, well, you can still try peddling it freelance.
So to speak.
Meanwhile, write another book, and not a direct sequel to the first book.
Lather, rinse, repeat.
(from a comment in madlori)
And in other news, "Follow Me Light" is live at SCIFICTION. This is an artist's challenge story, from one of elisem's lovely necklaces.
It's also An Unabashedly Lovecraftian Category Romance. (They said it couldn't be done.)
ETA: The handsome, charming, and v. talented Tobias Buckell (no, he doesn't pay me) is collecting data for a survey of genre advances here.
further ETA arcaedia talks here about how she would go about getting a literary agent. If, you know, she wasn't one.