The Kindle 3 natively supports documents in the .PDF format, and it is extremely easy to add or delete them from your device, via the USB cable.
1) First, attach your Kindle 3 to your PC. It should appear as a drive named “KINDLE”.
2) Next, locate the PDF file you want to add to your Kindle, using Windows Explorer.
3) Right click on the file and select “Copy.”
4) Left click once on your Kindle drive letter in Windows Explorer. In the right hand pane of Windows Explore, you should now see the folder structure of your Kindle.
5) Double click on “DOCUMENTS” – this is where we need to put the .PDF so it can be read.
6) Right click in the right hand pane, and select PASTE. This will copy your .PDF to your Kindle 3.
7) Now you need to safely disconnect your Kindle. Right click on the Kindle drive letter, and select “EJECT” like you would with a USB thumb drive.
8) Power on your Kindle, and you should now see your .PDF and be able to read it!