I had been thinking about what to say about getting an agent (a good portion of email that comes my way asks about this very problem) when Teresa Nielsen Hayden beat me to it, and did a better job than I would have, or at least a more thorough one. See this longish entry called, appropriately enough, on the getting of agents.
My agent history is short and sweet. My first agent dumped me because she couldn’t sell Homestead (somewhere in the discussion of why it wasn’t selling, she mentioned that it ‘wasn’t the kind of book that you’d see men reading on the subway’). More than that, she didn’t want to try to sell the other manuscript I had sitting there. So I did what most people do, I asked somebody who had an agent and she kindly pointed me not to hers, but to somebody else, and one of the junior people at that agency took me on. Thus was the happy match made; Jill promptly sold both Homestead and Into the Wilderness within three months of each other, for a combined very healthy mid-six-figure advance. Jill went off and started an agency of her own in partnership with another excellent agent, and they take care of everything. I’m very fortunate (1) that my first agent dumped me and (2) that I found Jill.
When I signed the Bantam contract I sent my first agent a postcard (I did want everybody in the office to read it, I admit) with the gory details on how much money was coming in. I sent another postcard when Homestead won the PEN/Hemingway award. Yes, now that you ask, I do have a mean streak if you prod me hard enough. But in my defense you should also know that I admitted to her she was right: to this day I have never seen a man reading Homestead on the subway.