Here’s a quick rundown. Kindle is very easy to use.
Kindle is mostly good for reading books; there are also publications you can read on it, but unless you get the large-format version (Kindle DX) that won’t be a pleasant experience. You can do things like annotations and notes, but it doesn’t sound like you would be very interested in that. Kindle is easier on the eyes for extended reading, compared to an iPad, for example, because of the technology of electronic ink vs back-lit screens.
Reading a book consists of going to the Home page on your Kindle, selecting a book from whatever is there, and then the book comes up on the screen at the beginning (or at the last place you stopped reading, if you had already started the book). You advance the pages by hitting a button. You can also go back to previous pages the same way.
Getting a book on the Kindle is a little more complicated. Once you receive the Kindle from Amazon, I think you can register it with them (or maybe they did that when you bought it, but I don’t think so). Then you can buy e-books from Amazon, or you can get free out-of-copyright e-books from various sources. With Amazon you can download them directly with wi-fi or 3G phone technology (if you have that version of Kindle), or you can download them to your computer and then copy them to the Kindle with a USB cable. The free book sites don’t offer wi-fi or 3G.
When you have read a book you can remove it from the Kindle if you want, although it will hold hundreds of books. After you have removed a book, it will still be on your computer or in your Amazon account, so you can re-load it later if you want to read it again.
When you are not reading, the Kindle goes into a sort of screen-saver mode, which actually saves power and prevents you from accidentall pushing the page button and going twenty pages ahead of where you left off. When you want to read again, you slide a button and the book comes back where you left off.
That’s all I can think of, but feel free to ask more specific questions, there are lots of Kindle owners around.
Roddy