Submit a query letter via e-mail with a few pages of the work pasted into the body of the e-mail (but no attachments, please). Response time is within five weeks.
“One seemingly obvious—but often overlooked—tip for authors is to proofread your query letter. It's the first piece of your writing that an agent will read. If I'm not drawn to your writing in your query, or there are lots of confusing typos, I usually assume that I'll feel similarly about the rest of your work.”