Remus:
I LOVE my paperwhite (Thanks BiL, ace xmas present).
If you buy one from Amazon, the first time you switch it on, it guides you through linking your kindle to your amazon account. I assume other are similar.
The you either search amazon for the book you want, or go to the kindle section on amazon, and have a look. There are 1000s of free books - most of the classics are free, as are the first in a series of many new authors. You tell Amazon you want the book, and next time your kindle is connected to the web, they appear on there. You don't need to be connected to the internet other than to get a book you've bought on there.
I've got a magnetic cover, and the thing switches off when I shut the cover, and wakes up when I open the cover. Swiping my finger across the page turns the page. there is a menu at the top, but its pretty simple.
You can also change the font size, and look up words you would like to know the meaning of in the inbuilt dictonary (tho it needs the internet for very unusual words, or bits from other lanuages).
I don't do APP's, smart phones or Ipads, and the kindle is fine.
Enjoy - it makes packing to go on holiday much easier - I've even put some kids books on there. Just been away for a week, and I took the kindle for me and the boys. DH took his tablet. No paperbacks - essential in these days of 10 cabin baggage travel!