Each E-Book is a PDF file. You will need a program which can open PDFs like Adobe Reader. You can download Adobe Reader here:

The 4-Book Special is contained in what we refer to as a ZIP file. The ZIP file is just like a folder on your computer which contains the 4 E-books in PDF format (see above).
Note: YOU DO NOT NEED TO PURCHASE ANY ADDITIONAL SOFTWARE TO OPEN A ZIP FILE as long as you have a computer running Windows XP, Windows Vista, Windows 7, or Mac OS X or greater. If your computer prompts you to download or purchase additional software, you may need to ask a professional for assistance.
Each Audio Book is an MP3 file. You can use any standard music player on your computer to listen to it like Windows Media Player, WinAmp, iTunes, and many more. You can also transfer the file to your iPod or other portable music device to listen to it on the go!