The numbers are underneath a scratchable layer, you scratch it off to reveal it, then enter the code.
No
In order to add funds on the Nintendo eShop, you can either connect your credit card and withdraw cash from there, or you can buy a prepaid point card which can be redeemed by entering the pin afterwards.
Yes, 3DS that are bought have eShop preinstalled.
No, you have to purchase the games with eShop money.
The content will go on your SD card.
No. As with 3DS games, prepaid cards are region locked. You cannot redeem a prepaid card bought in the US on the European eShop.
eShop codes can be purchased at game retailers such as GAME. They come in the form of a card with a scratch-off layer that reveals the code.
The eshop. The eshop is the 3DS's version of the wii shop channel. (please note that the eshop will not be available until 2011 late May)
It is already on the eShop for 3ds
The eShop for the Nintendo 3DS is out already.
$20 for USA and Canada. I'm not sure about other countries.
To add funds to your Nintendo eShop account, you must either have a prepaid Nintendo eShop card or a valid credit card. After launching the eShop, swipe to the right or tap the menu button to find the "Add funds" button. Alternatively, if you're looking to buy a specific game, do not have enough in your eShop account, and are paying by credit card, you can browse to the game you want to buy, then tap "Tap here to purchase." When the eShop tells you that you do not have enough to buy it, choose to add funds to your account, select "credit card", then select "needed" to add exactly as much as you need to buy that game. Remember that your eShop account is tied to your 3DS and cannot be used on another system.