Do your homework on the rules of publishing before starting out. For example, owning the International Standard Book Number, which can be purchased at isbn.org for $125, can help you retain publishing rights in the future to more easily create updated editions of your book and allow you to switch publishing platforms, says Marna Friedman, an Atlanta-based consultant who advises small businesses on self-publishing. But some publishers acquire ISBNs on your behalf, which means you'll need to stick with the same company for future editions, she adds. 

Not sure what to write about? Stay away from recapping your company blog posts or simply publishing marketing material. You want to demonstrate your expertise in a distinctive, engaging way, says Cavanaugh Gray, founder of Entrepreneur Café, a Chicago-based small-business development firm. "Don't get too theoretical or too technical, unless you are speaking to a very specific niche of readers." Both print and e-books can be as short as 100 pages or as long as 300, he adds. 

A big expense will be publication costs, which run about $5 to $20 per printed book. (Most e-books have minimal fees.) Friedman recommends choosing a publishing platform that offers a print-on-demand option, which lets you order books as needed rather than paying for a bulk order. Otherwise, you could end up ordering too many copies and getting stuck with leftovers. Sites typically ask authors to buy at least 15 copies to get preferential bulk pricing. 

You also need to factor in editing and graphic design costs which can together total $4,000 to $8,000, says James Altucher, a New York-based hedge fund manager who has self-published four books. If you're tempted to cut corners on editing and design, remember that a visually unappealing book with errors will hurt your credibility. "Nothing looks worse than grammatical mistakes in a self-published book," Altucher says.