New project, same agent?

My experience, and the experience of the authors I know, is that your agent is your agent. She reps you. Not just one work. So the way it tends to work is, "Hey I have a new work, I'm sending it to you tomorrow to get your thoughts!" You're a team now. This also means that you can also feel free to pitch ideas to your agent and ask for her input. I do that a lot. If I have several cool ideas and am not sure which one to focus on, she'll listen and then recommend what she thinks based on what's currently popular or what she thinks sounds most intriguing etc.

But you shouldn't have to query your agent every time. You're now in a "relationship" as it were. It's like with romance, you've gone on some dates, you agreed to be exclusive, and now you don't have to fret about "asking her out" anymore. You're a couple.

If you write two very different kinds of books—say romance and historic non-fiction, it's not unusual to have two different agents since they do tend to specialize.

My contract with my agent says I have to show everything I write to her before I attempt to do something else with it. Because I look to her for general career-shaping advice, if I do someday write something she doesn't want to rep, I'd probably take her advice about whether to query it elsewhere, self-pub, or bury it.

FWIW, she has urged me--in a gentle, without-direct-words sort of way--to get other things written in case the first novel doesn't sell.

Agent Jessica Faust just did a blog post on this here

From her perspective, she expects her clients to talk to her about all their projects. She sees it as part of her job to guide a career, which includes discussions about each project before they begin. I'm a little surprised your agent hasn't said, "Now that you're going on submission, what else do you have in the pipeline." The agented writers I know personally have all had that conversation with their agents.

ETA: LOL, what KT said

When I start a new project I usually send my agent anywhere from the first couple of chapters to the first 30% or so of the novel. And I say "Hey, this is what I'm working on now. What do you think? I'm hoping to have it done by August/the end of the year/next spring/whatever." I usually put something similar to a query pitch in my email to give him a sense of where the project is going, but I don't write it so much as a query as I do a very short synopsis.

With shorter stuff (like novellas) I usually try and send him the whole thing at once, but that's just me. FWIW, when we'd first sent my first novel out, I sent him an email with the synopsis and first chapter of the thing I wanted to write next and said "What do you think? Do you want to see more?" Since then I don't usually ask before I send him stuff, but that's because we've more or less established a method that works for both of us. Your agent may want to be involved earlier or later in the process, so definitely talk to her about what would help you out and what she's comfortable with.

Reiterating that, when you do get a career-based agent, they should be comfortable enough with whatever you write to at least judge whether they can sell it. Hiring an agent for contract advice on one book is another thing completely, of course.

So a frank discussion of your current and probable future genres should be part of the Call or Email you have with any agent offering you rep.