Expand your e-reader library with free ebooks

If you received an ebook reader as a gift this holiday season, congratulations! Now you've just got to buy some books so your Kindle, Nook, BeBook or other gizmo is more than a glorified paperweight. Or do you? Fact is, there are hundreds, if not thousands, of free ebooks available. You just need to know where to look. Like everything free, however, there are a few caveats to be aware of.

Check compatibility before you download free ebooks

Much like MP3 players, there are dozens of ebook readers available. And like digital music, file compatibility is an issue with e-readers. If you own a Kindle, for example, you won't be able to read ebooks that use the common ePub file format (something other popular e-readers, like Barnes & Noble's Nook, Sony's Reader and Apple's iPad can do). All but the first generation of Kindles will read PDF and TXT files, two other common formats for free ebooks, however. If you do own a Kindle, an application like Calibre will convert ePub files into a compatible format.

Not sure whether your e-reader will accept a particular format? Digital media talk show host Kim Komando posts a compatibility chart on her website. Jason Hildalgo, About.com's guide to peripherals, also posts an format compatibility chart on his website, although it's from 2009. (Note: ConsumerSearch is owned by About.com, but the two don't share an editorial affiliation.)

Keep your ebook expectations in check

Although there are an untold number of free ebooks available, you're not going to find the latest bestsellers among them. Free ebooks are, for the most part, older publications whose copyrights have expired and are now in the public domain -- and that's a fairly rich vein of literature to be mined. Classics by Mark Twain like "The Adventures of Huckleberry Finn" and Jane Austen's "Pride and Prejudice" are easy to find, as are historical texts such as Alexis de Tocqueville's "Democracy in America" and Karl Marx's "The Communist Manifesto." Depending on the site, you can also find titles by H.G. Wells, Lewis Carroll, Oscar Wilde and Charles Dickens, not to mention children's classics such as "The Tale of Peter Rabbit," "The Wonderful Wizard of Oz" and "Peter Pan."

You can also find sites that specialize in technical and scientific texts, not to mention public documents issued by federal entities like the Government Accountability Office. Retailers like Amazon.com also offer free ebooks by contemporary writers, although most of them are by unknown writers who are self-publishing, and the titles lean heavily toward romance novels and self-help books. But the books are free, so it doesn't cost anything to take a chance. Who knows? You may discover a favorite new author. Or not.

And don't forget your local public library. Ebook titles are still rare at many institutions (the New York Public Library only lists 100 titles on its website, for example), but this will change as time passes and ebooks and e-readers become more common.

Reliable sources for free ebooks

Surf the web and you'll find countless sites offering free ebooks. But be careful. Some are spam sites fishing for dollars, some require memberships, and some are free and legitimate. Here's a brief list of some sites that are worthwhile:

• Project Gutenberg: The granddaddy of free ebooks, Project Gutenberg has been around since 1971, when it was created at the University of Illinois. Popular titles to be found here include "The Adventures of Sherlock Holmes" by Sir Arthur Conan Doyle, "Ulysses" by James Joyce and "The Kama Sutra of Vatsyayana."

• Google Books: Google is a pioneer in the digitizing of texts (though it has gotten them in some trouble with publishers and authors), and you'll find not only books but also magazines (though copyrighted material cannot be downloaded). Titles include Edith Wharton's "The Age of Innocence," Albert Einstein's "Relativity" and Walt Whitman's "Leaves of Grass." You can also peruse reader reviews of the texts.

• Amazon.com: The company that revolutionized online book sales is also a source for free ebooks (and ones you pay for, too).

More ebook resources

We found a number of sources that list free ebook websites. They're a grab bag of general-interest and niche sites, and not all of the links are worthwhile. But part of the fun of surfing the web is exploring, so grab your mouse and start clicking!

• About.com's guide to web searches has a good list of ebook sources and is a trustworthy site to visit.

• Mega-PDF.com is a PDF search engine that can help you locate titles online.

• Feedbooks.com, like Amazon, sells popular ebook titles and also offers free public-domain texts and ebooks by new and unknown writers.

• The blog Tech Tools is an enthusiast site with a list of 50 ebook resources, as well as other resources for the web.

• Archive.org is a non-profit website dedicated to preserving publications, audio recordings and film and video for the general public, academics and researchers. You can literally spend all day here exploring.