Go to your battle.net account management homepage.
Click on "Add Games"
Click "World of Warcraft Battlechest"
Click "Serial code/Have serial key"
Enter the Serial code provided when you purchased the battle chest.
If you ave the current battle-chest then you will need to upgrade first to Cataclysm, and then to Mists of Pandaria (that's two upgrades), either by purchasing a digital license or using a license from the boxed physical sets. The battle-chest comes with World of Warcraft, The Burning Crusade expansion, and the Wrath of the Lich King expansion.
There is no Battle Tank mount in World of Warcraft.
There is no "Fast" way to do it. You simply just allow the installation discs to run their course of getting all of the files on your computer. Alternatively, you can download the games from the World of Warcraft website.
World of Warcraft has a fixed monthly fee, usually between 8-9 pounds, which can be reduced by paying in 3 or 6 month installments. This is regardless of which expansions you have installed, so it doesn't matter whether you buy the regular WoW, battle chest or have Mists of Pandaria (the latest expansion).
Yes, although Classic and Burning Crusade are molded into one in the WoW: Battle Chest.
No, there are no Pokemon in World of Warcraft. There is a mechanism to catch and battle critters found in the world.
There are roughly 9-10 million active subscriptions for World of Warcraft.
There are two versions of the Battle Chest, both are identical except the medium that they come in. One medium is the normal boxed disc. When you receive it, you do not need to download it. The other medium is the digital download. You can download it right after purchasing it, and there are instructions on how to download it when you check out.
The newest World of Warcraft expansion is called World of Warcraft: Cataclysm
Currently, as of August, 2012, there are 10.2 million active subscribers to World of Warcraft.
2 1x World of Warcraft 1x World of Warcraft:The Burning Crusade
The battle chest is a special packaging/promotion that Blizzard will put out after a new expansion. It contains the original World of Warcaft client along with the Burning Crusade expansion. It also contains guides and manuals for both the original and the expansion. Note: it does not contain Wrath of the Lich King or Cataclsym. It is unknown at this time if Blizzard will release a battlechest for wrath and cataclysm.