Barbara,
Click on the following URLs, or access them from your Kindle. Download the files. If you download the file to your computer, then you will need to put the files in your documents folder via USB:
https://www.mobileread.com/mobiguide
http://www.feedbooks.com/kindleguide
Afterwards, you'll see the two guidebooks on your Kindle. You can click on links inside them to download free books.
The browser isn't exactly the same as whispernet but it uses whispernet to download things, just like the Kindle does with Amazon books.