Go to audacity.sourceforge.net and download the free sound-editing software Audacity.
Soundproof your recording area. Before you begin recording you must cancel out as much white noise as possible. Find the quietest room in your house and turn off anything that will cause background noise, such as TV, DVD players, overhead fans, air conditioners and heaters. Close the door and windows, pull the shades down, and put a rolled-up towel under the door.
Decide how you'll divide up the material. You'll have to break the book into several MP3 files. Know ahead of time how many chapters each MP3 file will be so you can plan your recording sessions accordingly.
Record and edit your audio. Record one session at a time. If you stumble over words, keep recording and say it again; you can go back later and cut out the extra word. When editing audio, it's always easier to cut things out than it is to re-record sections, but you will have to re-record some things. Open a new file, record the new section, and copy-and-paste it in.
Insert music at the beginning and end. You can find "podsafe music" for your audiobook at musicalley.com. You can use music to enhance the listening experience and make the audio sound more professional.
Export to MP3. When you're finished recording and editing, click "file" and "export to MP3." You'll be directed to fill out ID3 tags. These allow people to identify exactly what they're listening to on their media player.
Distribute your audiobook through podiobooks.com or libsyn.com if you want to give it away or on e-junkie.com if you want to sell it. You may also be able to sell it through Amazon on audible.com.