When you get your Kindle you'll need to register the serial number with Amazon who then set up with a Kindle account. When you buy books from amazon you select the Kindle edition (rather than the actual book) and it will automatically send it to your Kindle. Then when you next turn the Kindle on it will update and download your book (takes seconds). As you have 3G you'll be able to do this anywhere, not just when you're connected to wifi. The Kindle also has a very basic web browser which is free to use, but not much cop really (but then it IS free).