To self-publish a book is the ultimate do-it-yourself project. You not only write the book, you also lay out its pages, illustrate it, select paper and binding, print and bind the book (or find a book manufacturer to contract out the printing), and then comes the joy of selling your book. That's how book publishing was done in times long past. Self-publishing is enjoying a renaissance today, thanks to the Internet and software which makes this herculean task much easier. Also, self-publishing is more profitable compared to the alternative -- when it is done correctly.
Book publishing companies are not very effective for authors these days. They are awash in book proposals and it may be years before they get around to rejecting yours. They publish books at a record pace, but only a tiny fraction of proposed books are ever published. Then, those "lucky" books enjoy average sales of only 3,000 copies over their lifetimes. Authors are paid meager royalties and are forced to assume an increasing share of marketing and promotion work; often, authors are pressured to buy their own books in bulk and go sell them on the road! You may as well publish your own book and keep all the profits.
There are many books about how to self-publish a book. There are also Web sites devoted to at-home publishing and self-publishing books. There are even complete software packages that contain all the tools and information you need to self-publish books. But the basic steps are pretty easy.
Write your book in a word processor such as Microsoft Word or Open Office (the open source alternative productivity suite from Sun Microsystems). Using your own camera, graphics software, and public domain clipart collections, illustrate your book. Then compile the book as a PDF file using Adobe Acrobat or a low-cost alternative such as Foxit PDF Suite. You now have a digital version of your book.
You may want to skip the printing part of self-publishing all together. Printing is the bulk of self-publishing's expense, and it really doesn't add much to sales; see the average sales figures above. But if your ego demands a "hard copy" as proof that you actually published a book, then go with one of the print-on-demand services that will print very small quantities -- as few as one copy at a time. Don't spend money on printing until you have a customer's money to spend.
You can publish a PDF copy of your book on many online platforms such as Scribd.com, where you can upload your book and set a price for downloading a copy of it. The site takes care of getting your book indexed by search engines so people find it, presenting limited previews of the book so they can sample it, taking credit card or Paypal orders and allowing downloads, and sending you the net profits after the site's service fee. Self-publishing a book has never been easier!