I'm writing my first draft of my first novel right now, and resources like these are invaluable. While I'm still at the dreaming stage when it comes to looking for an agent, I keep a mental list of people whom might be the right agents to query when my novel is ready. I'm not married to this list in any way, and I encourage people at the early stages of a novel not to set themselves on one agent because tastes change--your taste (I'm sure my third draft will look worlds different from my first, and that will mean cutting potential agents from my list because they won't want what I'm peddling) and an agent's taste. Remember to check submission guidelines every now and then, and always read them thoroughly before querying. Even if you love an agent to pieces, never expect them to change their preferences because you've written what you think is gold.