It's very easy to use as it comes with a really simple,
easy to understand user's guide.
The one I got is not only Wi-Fi enabled, but also has 3G. I don't actually know what 3G does, beyond that I had to wait until the latest version of Kindle was equipped with it to be included in their coverage area.
You can see at a glance what books you have by going to the home page. I'm not sure yet how many titles it will store on the home pages; so far, I have two pages to access when I click the 'home' button.
Pressing the 'menu' button enables you to turn the Wi-Fi on (I've found the battery charge lasts for 10 to 12 days if I only have the Wi-Fi on when I'm shopping for new books).
You can get free samples of a book to read before you purchase it. There are also many, many books that cost only 99 cents or are totally free! Some books are 'text to speech' enabled, which means that the book will be read to you. That's very handy if I have a migraine, but the quality of the reading is very poor and almost sounds, at times, like it is an electronically generated voice. That's something Amazon could definitely improve.
One feature that I really like is the ability to change the size of the font. You can go from teeny-tiny to huge, with many sizes in between those two to choose from.
The cover has a cool little reading light that pulls up out of the upper right corner. It has two tabs on the inside that slide into two ports on the left side of the Kindle, thus enabling the light to be powered by the Kindle battery. However, I've found that the battery will need recharging much more quickly if I use the reading light.
The screen isn't back-lit and is really easy on the eyes. It's not anti-glare though, so you do have to adjust the way you're holding it if you're reading in a bright, direct light to avoid glare.
When you're not reading, you slide a button on the bottom of the Kindle to put it in 'sleep mode' and this helps extend the battery life also. There are a lot of different pictures of various authors and things that it cycles through each time you put it to sleep.
What I like best about the Kindle is the extremely light weight. I have some medical conditions that are starting to make it very painful for me to hold large, heavy books for more than a very brief time. Kindle solves that problem for me.
But will it ever replace 'real' books for me completely? NEVER. I just love books too much; the scent of them, the texture, the covers (on some), the feeling I get when I open a book that I'm actually stepping into another world. I have no doubt that I'll buy a book in hardcover after I've read it on Kindle just so I can have all those experiences if it's a book that I really love and is available in hardcover. (There are quite a few books that I love that were never released in hardcover. Stupid publishers!)
Of course, good writing will transport me into the world of the book I'm reading, whether it is a 'real' book or a book on Kindle...it's just that the transition is a little easier for me with a 'real' book.