If you know better or have had different experiences, please share in the comments, but this is what I've learned so far:
1) The Interview - If you have the opportunity, first talk to the editor interested in buying your book. I had the chance to do this with various editors the day before the auction for TETHERED. I believe the really savvy editors do this and I like working with savvy people. It also gave me insight into what edits they envisioned for my manuscript. For me, some terms were non-negotiable, I would rather stuff my book under the bed than change certain scenes. The editor I really, really, really wanted to work with, the one whose suggestions I believed were brilliant, is now my editor. That phone call made all the difference (for me).
2) Rights - When your lovely agent fields offers for your book (oh, blessed day!), you may need to decide whether to sell World or North American rights (I've heard there are subcategories for English-language, Spanish, etc, but let's stick to generalities). There are pros and cons to both. If you were to sell only NA, your agent could then sell foreign rights through her contacts abroad. These dollars would go directly into your pocket (with your agent taking the standard 20% on all foreign sales). That's very nice. If you sell World, what your publisher sells goes toward your advance; the publisher takes 25%, you take 75% -- UK is a 20-80 split -- and that 75% (minus your agent's cut, I believe) pays against your advance. Conceivably, you could earn out your advance even before a single book is published and it builds A LOT of enthusiasm in-house when the foreign rights team gets sale after sale. Everyone notices. Very nice. Oh, and I had no idea foreign rights even paid anything to the author, much less could be equally or even more lucrative than the domestic advance. Very, very nice.
3) The Contract - Read it. Even if you think it's all Greek, read it. You may very well save yourself and your publishing team a headache. You'll no doubt learn what rights you are and are not afforded when it comes to your work. Each contract is negotiated on its own terms, so I can't generalize, just read it. Oh, and you do know your advance is divided into thirds (usually, though fourths if it's 6 figures), right? The first third is paid out upon signing the contract, the second upon delivery & acceptance of edits (d&a), and the third on publication day. It's like Christmas all year.
4) Cover Art - What a revelation: I know very little about book covers. I know what catches my eye, but I don't know what sells books. When my editor emailed my cover concept, it wasn't anything like I had long imagined (see photo above). Instead of reacting, I looked at this website and this one. That's when I realized it's better to leave this sort of thing to the professionals, they know the market, they know what attracts booksellers and buyers. So I defer. And I do like, really like, the latest concept I was shown.
5) Edits - Editors do edit -- at least mine does. You've heard a thousand times they don't anymore -- oh, where have all the Max Perkins of the world gone, they lament. My editor's been over my manuscript three times now and has spot-on suggestions. She not only sends me editorial letters, she wants to talk through the details. In fact, everyone I know who's sold a book this year has had the same experience. And listen to your editor, even if you initially don't agree with the points made, mull them over. Try. This is why it's important to refer back to #1.
6) Title -- Kristen asked about this one. I was convinced mine would change, so I prepared myself for it. The title of my novel was originally Living, but after the first chapter, I changed it to TETHERED. I never allowed myself to marry it, though, a writer shouldn't. An agent or editor can change it at any time usually for good reason. In fact, right before my agent sent it out, she suggested we come up with a few alternatives, but none were quite right. Besides, she said she'd been buzzing it to editors for so many weeks as TETHERED, we had that all important name recognition. So far, my publisher hasn't suggested changing it -- though I remain open to all possibilites, we must be -- and I haven't said a word. Shhhh.
7) Catalog Copy - Remember back when you were querying agents, trying to summarize your 80,000+ manuscript into one measly paragraph? That nut graf is essentially your catalog copy, the brief paragraph that goes in the publisher's catalog that is then sent to booksellers. Walk into your local independently-owned bookstore, ask the owner (they're wonderful people, ask) to show you all the catalogs on her desk, and you'll realize how important that one brief synopsis is even beyond the query. Don't worry, you'll have an entire team working with you, but you know your book best.
8) Author Photo - The inestimable Ron Hogan of GalleyCat fame summed it up best. A good photo tells the world you care about your career. Don't scrimp. I've squandered good money sitting for good photographers who don't know the subtle art form that is the author portrait. Entirely my fault, I was trying to save money and lost it instead. Go to an experienced photographer who specializes in this. It matters.
9) Blurbs - For some inexplicable reason, I thought asking my favorite authors for a blurb would be fun. Then I read this and this. Warning, don't hit the links, especially if you also thought it would be fun. To be honest, I've had several extremely generous people agree to read my book -- notice how I didn't write blurb my book? That's because they may discover they don't actually have the time or think my writing is substandard or the story itself is somehow inappropriate with the trajectory of their careers. There are many schools of thought on asking for a blurb. I prefer to write personal letters, but some authors may want to be approached by an agent or editor, or there's an established relationship there. Talk it over with your team, you're not alone. But when I think about it, the idea of these amazing authors reading my work makes me nauseated, they're so good and I don't measure...STOP. Don't let yourself think about them reading your words. Just don't.
10) Glaciers - The day after my book sold, my agent warned, don't worry if you don't hear from anyone for a few days, things are going to get quiet. Nope! How many times have you been led to believe that this business moves at a glacial pace? That's not been my experience. Maybe it's because TETHERED sold in October and will be released in September that everything feels as though it's clicking along, too fast, but I know others whose books sold about the same time but will be released later and they've had the same editorial schedule. Whew! Invest in Starbucks.
11) Expectations - Manage them. But also shoot for the moon, you just might land on a star.