Download the MP3, or other format, files that contain the sound for your audio book. Be careful to note what you title them and where you save them so that you will be able to locate them easily.
Place your cursor on "Start," which is the green button at the bottom of your PC's screen with the Windows logo on it. Double click. Look for "All Programs" at the bottom of the menu that pops up, and put your cursor on it to highlight it. You will now see all the programs you have. Find the name of your CD burning software and double click on it.
Find the button on your CD ROM drive that allows you to open it. It will usually be on the right side of the drive. Press the button gently and wait for the tray to come out. Insert your recordable CD, shiny side down. Then press the button a second time to close your drive.
Turn your attention back to the window for your burning software. Look for an icon that resembles either a musical note or a speaker. Click on it. Now find the option that says "Music DVD" and click on that. Although your book is not technically music, it is all the same to the computer--audio rather than video.
Go to "Start" like you did in Step 2 and click on "My Computer." Find all of the audio files you need for your book. Select each file and right click on it. Then drag it to the window left open in Step 4. It will say "drop files here" or something similar in the exact place where you should put them. Once you have all of your files dropped in place, the software will copy them so they don't get deleted off your PC.
Select the options you would like by clicking on the boxes next to them. Then click on the red button and your files will burn to your CD. It will take some time, so make sure your computer doesn't shut off or eject the CD before everything is ready.