Since I'm with a small press, I'll add a little bit to this board.
Advance - no, I didn't get one. No, that doesn't bother me, since I know this publisher is both legitimate and new, and wants to sell books. They took me on when I was unkown (I know that sounds like a PA line, but really, a lot of small publishers don't give advances) For me, it really is a foot in the door. My queries for my current work look much more impressive with my newly released book on them
Oh, and I absolutely know I had to beat out a bunch of other manuscripts to get a contract - this publisher only puts out about a dozen books A YEAR, and they get tons of subs a month.
Editing - like with the big publishers, my book was assigned to an editor, and when it was my turn (took about three months after the contract was signed to get to the head of the line) David (David Lee Summers, another SoS contributor) and I went back and forth for six-eight weeks on changes. Didn't have to change a ton, but it's not a huge book either, only about 50K words, average for a middle grade book.
Cover art - and illustrations. You can see the cover if you click on the publishers link in my sig. That part took the longest, about six months, because each of the eight illustrations and the cover are done by hand by an amazing artist, Robert Nagy. And he had to actually read the book to get ideas about what he wanted to draw. He's got his own website here:
www.meltingmind.net
Galleys - my manuscript was formatted (looks so nice!) and the file sent to me to look over. Once that was done and changes made, illustrations added, etc... the file was sent in .pdf form to me, the editor in chief, and my editor for final approval. (by the way, I'm still looking for reviewers, so if anyone wants the .pdf, I'd be glad to send it along.)
Promotion - here's the big diff between small and big presses, I think. Yes, my publisher is going to do promotion. They have a publicist, nice, nice lady, and she gathers all the stuff for the media kit (yes, a real media kit), but I helped to write it up. She's going to fill out all the paperwork to get my book to the big box bookshop chains, which is a big process - I've seen the paperwork. And she's there to consult with if I need help.
BUT... I'm doing a lot of promotion myself. Setting up my own launch party, getting my signings, etc... Yes, I have bookmarks, but the art director for the publisher designed them, and I had them printed up at Staples and cut for not a whole lot of money. (I have to say, Jenna's e-book "Book Promotion Ain't for Sissies" has been a big help!)
My little publisher is going to do everything they can to get the books out there, but without a big name behind them, it's tougher. They want to sell books, and are going to make every effort to do so, unlike PA.
Differences from PA - my contract is NOT seven years; if, for some reason during the process, either of us had problems, we could terminate the contract; I know my royalties will be spot-on; and I don't have to buy my own books- I CAN, for a nice discount, I need additional copies for promotional purposes or for gifts, but my book's success does NOT depend on it.
There you go. Not big house publishing, but commerical nonetheless.