How do I find a publisher for my book?

First off, I'm glad that you're preparing a proposal rather than trying to shop around an already-written book. In my experience with over a dozen different publishers, trying to find someone to publish an already-written book is considerably more difficult because each publisher has their own preferred style and format into which you end up having to recast your manuscript.

As a general rule of thumb, I always encourage you to look for publishers that have had success with similar titles, rather than trying to convince a publisher unfamiliar with that market segment. Selling a technical book about open source software, for example, is quite different to selling an intro book on Windows XP!

Then there's the whole question of book production too: a technical book requires a different and more accurate editorial cycle than a more theoretical book. If the book includes specific lines of code or program snippets, someone is going to have to double check that everything works correctly (that's the technical editor), a requirement that isn't there on most books. For the same reason, the development editor and copy editor need to be familiar with more technical titles too, or your carefully crafted code examples will be reformatted to fit some layout requirement and end up broken. (I have heard stories of overzealous editors fixing grammar in software listings, for example, or changing quotes to match a standard English usage style, even though in almost all languages a single, double and back quote are dramatically different, not to mention the confusion from turning straight quotes into so-called smart quotes!)

To find these publishers, either go a local bookstore that has a strong technical books section (there are still a few left, like Nerdbooks in Dallas, Texas and SoftPro Books in Waltham, MA and Denver, CO) and ask the person who purchases related titles (in your case, that'd be open source titles) about what publishers have the most interesting books, sell the most, and are easiest to work with. That'll be great data, and you might even ask if they can make an introduction to someone at the publisher too.

If you don't have that option, you can use Amazon.com to do some research too: search for related titles, then note the publishers. Probably you'll see O'Reilly Media, CRC Press, Prentice Hall, Digital Press, etc., since the more well-known publishers tend to stay focused on more consumer-oriented works. Pick the two or three that sound the most promising (or pick 'em randomly just to get started), then use Google to find their individual Web sites.

All tech publishers are delighted to get unsolicited proposals, so it's a sure bet that they'll have "become an author" or similar links on their site that lead to extensive discussions of what they seek in a book project. For example, buried on the bottom left of their busy home page, O'Reilly Media has a link to "write for us" that's well worth reading.

O'Reilly offers some invaluable advice on how to send in a proposal too:

When I send in a proposal, I tend to include no more than a single paragraph about the actual book I am interested in writing so that I don't waste anyone's time with too much information. If the short description is engaging, then they'll respond favorably, inviting you to send them a full proposal. If they aren't interested, you might ask yourself why rather than just crossing them off your list. Is the title not marketable? Is the product you want to write about unpopular or eclipsed by a new system? Did you have an incoherent proposal message? Do they already have a book on the subject or - though you couldn't know this - a book in production?

Always make sure to explicitly copyright anything you submit too. I had a very bad experience when I was first starting as a writer where a publisher asked me to submit a full expanded proposal (which has about 1/3-1/2 page description of each chapter) and then promptly told me they didn't want to proceed with the book, hired a freelance writer to produce the book from my outline, then published the book I had proposed in the first place. You do not want that to happen with your book idea!

Anyway, those steps should get you started. If you have specific questions about contracts, contract terms, negotiations, etc., please don't hesitate to come back and Ask Dave Taylor!.