Q: I've just written and published an e-book on Amazon.com. What do I do now? Should I try to publish it with a major publisher?
A: That's great about publishing an e-book! People all over the world can download it and read it (transferring to sales for you).
The first thing I'd recommend for you to do is decide what your goals are for this book. Do you want a print version (and why?) Or are you okay with keeping it an e-book? The answers I give you will vary greatly according to what your purposes are for your e-book.
For starters, if you'd like a print version, you can either 1) self-publish and market your book yourself in a print version, or 2) try your luck with a major publisher. Self-publishing is easy enough if you have funds up front, but you'll still need to market it yourself.
As for publishing with an established publisher, I can almost guarantee you right off the bat that going the self-publishing route will be much easier. It's extremely hard to break into major publishing markets nowadays even with an agent - and if you don't have an agent, and a good agent, that's another big hurdle. In the past it was easier. You could simply send query letters straight to editors at publishing companies, and they'd send you a letter back with a rejection slip or an offer to dialogue further.
However, publishing is nothing like that anymore. YOU CANNOT SEND QUERY LETTERS DIRECTLY TO EDITORS. I don't know of a single publisher who accepts query leters anymore. They all work through agents - and agents only. Barbour Publishing, the company I work with, used to be one of the last to accept query letters and now no longer does. You must have an agent to deal with publishers. And in order to get a good agent (be careful with this - there are a lot of scammers out there!), the main solution is to circulate among writer's conferences, land an agent interview, deliver a good pitch for your proposal, and pray you get signed on. And even then it's no guarantee you'll get published - but it's a start.
Back to publishers and the question about publishing with a major publisher. One of the biggest mistakes many people make (myself included, I've done this in the past) is to send manuscripts and queries (remember, they don't accept these any more, so they'll probably all go in the trash anyway) to a list of publishers straight off a list. This doesn't work because publishers each have their own "niche" in the market, and your e-book is not going to fit all their various platforms. Publishers make a name by publishing one kind of thing (like Barbour publishes fiction and historicals) and rarely break away from that because it shatters the image they've worked years to create. Not only will submitting materials be unproductive because publishers don't accept query letters directly nowadays, but it'll probably tick off the editor because 1) you didn't read up enough on the publisher to find out that they don't accept query letters, or worse 2) that you didn't read up on them enough to know what kinds of things they DO publish.
If you do have some connections in the publishing world or an agent, one thing that might help is to try markets that are tailored to your specific topics (like publishers that have published lots of non-fiction titles about money, homeschooling, or the like if you're writing about homeschooling education/finance plans). If you try publishers that are way off in left-field for your topic - like one that publishes science fiction - it'll not only get rejected, but again, the editor (if it even reaches the editor at all) will probably be steamed that someone didn't do their homework about what they publish and what they don't. And it'll burn bridges for you if you ever DO write something that might fit their market!
In general publishers don't vary much at all what they produce - much like Sears doesn't sell livestock, and McDonald's doesn't sell plumbing equipment - or even something slightly different, like spaghetti.
As you can see, turning an e-book into a print book is a lot harder than simply marketing it and selling it online! And I'd have to ask WHY you want a print book. The book industry has changed so much that print books are on the wane (to a certain extent) and not really necessary nowadays. If you're after sales, my recommendation would be to continue marketing your e-books as an e-book unless there's a real reason to do otherwise (or you have the funds to print it and market it yourself).
So we're back to number one: marketing the e-book you already have. There are a million ways to market the book you already have. Getting notoriety on Amazon is a biggie - perhaps the biggest of all. Get reviews. Promote your e-book through word of mouth. Post it on Facebook and other social networking sites. Ask friends who have read your e-book to leave a review on Amazon. Blog about it and give away free copies to blogger and book reviewer friends.
And... that's the little bit I've learned in my short (year-and-a-half) journey with publishing.