Kindles are very easy to use, but a few things you need to do:
1. Create an Amazon account for yourself if you don't already have one.
2. Once you receive the Kindle charge it up fully before you start messing with it. If you're getting a "new" style Kindle (i.e. the one without the keyboard) note that the Kindle doesn't come with a charger, just a USB lead you can charge it with from your PC, or a compatible charger (the one for my mobile phone works OK for me, but may not for you.) Maybe consider buying a charger for the Kindle from Amazon or a Kindle stockist.
3. Once charged, take your Kindle to a wifi hotspot. Turn wifi on on the Kindle. Connect to the wifi hotspot and register the Kindle (simple process). There may also be a software update for the Kindle.
4. The Kindle has a user guide pre-installed on it. Read it - all of it. It will get you used to operating the Kindle, plus it will get you used to reading from it.
5. If you have the Kindle with the keyboard you also have 3G which will work globally so you can buy books directly from Amazon wherever you are, providing you can pick up a 3G signal. If you have one of the newer Kindles without a keyboard you can only download via wifi or via a computer with your USB cable.
Ultimately the Kindle is very easy to use. My 81 year-old father in law has one and is regularly downloading books for himself via 3G, as does my 67 year-old father.