Just email the book (as an attachment) from your gmail account to your Kindle email address then have your Kindle connect to a WiFi network to download the book.
I use the
xxx@free.kindle.com email address, and have a wireless home network, so I just switch WiFi on in the Kindle, it hooks up to the network, and the book downloads onto my Kindle (no 3G on this Kindle, just WiFi).
- Donna