go to this website and sign up for the notification email:
http://www.ereaderiq.com/
They comb
Amazon daily and email you with links to the latest free Kindle books. You need to act quickly though because sometimes they go off 'free' fast!
To download Kindle books without Whispernet, you'd save the book to your computer. Then you'd attach the parallel cable from your computer to the Kindle and move it.
I find good books on
www.smashwords.com also. If you do a search on 'free Kindle books", you'll find lots of websites.
Good luck- DH and I both love ours....