I attended the Green River Writer's Novels in Progress workshop. (Link to come, but in the meantime you can google it.) It's held every March in Louisville, Ky. There I met an agent, who liked my book and agreed to represent me. He basically handled things from there.

I highly recommend attending workshops like these -- not only for the writing skills they help you with -- but also for the opportunity to talk to agents about your idea and it's marketability. Even if they don't ever agree to represent you, they will give you valuable insight into the publishing world. And get you more comfortable in pitching and discussing your book. (You may also find that being forced to explain the plot in two sentences helps you, ahem, decide what the plot is.)

Plus, the whole process becomes less intimidating when you know they're just people too!