Congratulations, you've got an agent and a manuscript in submittal, or you've got an offer on a self-submitted novel and you're scrambling to call your first-choice agent.
The first thing is to realize that you're going to keep raising the gates on yourself. This is normal. At the beginning of my writing career, my goal was "Finish a novel." Then I accomplished that (and I really felt like I deserved flowers, but what I got was a beer--) and the quest became, "Finish the second novel, and find an agent for the first one."
If I could only finish a novel, I had told myself, I would feel like I'd accomplished something. And I did. But then, having finished the novel, I had to figure out what the hell to do with it. If I could only find an agent, I told myself, I would feel like I had accomplished something. And then, having found an agent (with the fourth novel, rather than the first, see "keep writing" below) it became gee, if I could sell this novel, I would feel pretty good about it--
This summer, I chanced to meet a very nice person who also happened to be a very successful SFF writer. "If I could just get onto the New York Times Best Seller List again," quoth the Writer, who happened to be somebody whose books I devoured in college, "I would feel like I'd accomplished something."
And I blinked at the Writer, and I said, "I'm sure you will."
Because it was all I could think to say. (I am not fast on my verbal feet, as those who know me will attest. I'm a pretty good thinker, but not so nimble about it, and if somebody interrupts my chain of thought to argue before I get around to explaining to myself what I meant, all I can do is shrug and say "I'm sorry, but I don't remember what I was saying." Because, well, I don't.
I didn't last on the debate team, no. *g*)
But what that random comment brought home to me, itty bitty little neopro with two books to my name, was that success is always just over the next jump. And this gate-raising isn't a bad thing, because it keeps you a bit hungry.
The second thing is to keep writing. Trust me, even if you are not a particularly fast writer, you can finish two (or three, or four) drafts in the time between submitting your first novel to an agent and her selling your fourth one.
In my case, this worked out particularly well, because by the time arcaedia had read and rejected my first novel, I not only had two sequels finished, but a second draft of Hammered. So when she oh-so-politely said "I don't think this is right for the market, but do you have anything else I can read?" I could say "Why, yes!"
And by the time Hammered sold--elapsed time from first query to agent to sale of first novel, approximately 18 months, which is extremely fast--I not only had a draft of the sequel, Scardown, done, but I had a draft of Blood & Iron and was working on The Stratford Man. And I kept writing.
Which puts me in the position I am in now: I have three books out this year, two coming out each in 2006 and 2007--three of those written or mostly written at this point--and I have seven more completed novels that need to be revised and sold.
In addition to a bunch of short stories.
Not everybody can write two books a year. I, in fact, have been doing it for a little bit too long right now and badly need a break. But most people can write one book a year. And if you can write one book a year, you can have two books finished by the time your first novel sees print, on the fastest probable schedule.
Write. And write with breadth, write in all the genres it interests you to write in, because if the fantasy doesn't sell, the mystery might.
Keeping one's self in front of the audience is a good thing.
The third thing is to accept that you will panic. Writers is nuts. We know this thing. It is, as stwish would say, a Known Fact.
The three months surrounding the publication of your first novel will be a nightmare. You will lose sleep. Your concentration will suffer. You may drink heavily (we don't recommend this), take up smoking, or engage in unsafe stranger sex.
This is normal.
Not healthy, mind you, but normal.
Get back to work. The level of celebrity you are likely to encounter once the book is out is minimal, and the next book has to be written anyway. You might as well get a jump on it.
Besides, by the time the third book comes out you're likely to be totally focused on the fifth one, and to have actually forgotten the first one to the point that when you see something in a review that seems wrong, you actually have to go reread your own novel to see which one of you bitched up that plot point.
And while you can sell books you haven't written, you can sell books you have written, too. And see them in print that much faster.
And if your publisher should happen to turn down your option novel--as happened to me--if it's a complete draft rather than a proposal, it's that much easier to turn around and shop it to another publisher, and pitch something else at the first publisher.
Inventory, in other words, is your friend.
The fourth thing is that once you get to publication, you'll find yourself looking around and blinking and thinking "wasn't this supposed to be harder?"
This is the time to remind yourself that it was harder.
You've just blocked that part out.
This is the part where you get to be an overnight success after fifteen years of trying. Try to enjoy it a little.
Because the fifth thing is that desperate scramble to get out of the mid-list and into someplace with a little job security.
I'll let you know how that part goes in five, ten years.