could some one explain to me how a kindle works... do I need to use my computer with it while downloading book?

You can directly download the books from the internet. You do not need a computer to use it.

Here are some interesting FAQ's about kindles:

http://budurl.com/KindleRegularFAQ

And from my bookmarks you can get some useful info here:

http://budurl.com/ChooseKindle

You can use the kindle on its own to download books - either by wifi or 3G depending on the version you buy. 3G is free.

You can also use PC or MAC kindle software to download books - you can connect the kindle via usb and transfer books that way if you wish.

You get a plug to charge the kindle. You can also charge it by plugging into the usb slot of a computer.

It is a stand alone unit, has a wall charger. 3G wireless down load. Buy your Amazon gift card or use your debt card to shop for your books and read to your hearts content. Holds over 5000 books and they can be deleted if you want.