That package contains everything you need for a two-player Magic game. When you rip it open, you get two boxes:
In each box, there's a Magic 2012 Booster Pack and two color-specific groups of cards. At this point, we're going to move from the world of theory to the world of acutality. Which is a fancy (and possibly inaccurate) way of saying I played a Booster Battle Pack game against Daily MTG editor Kelly Digges. So from here on out, you'll be seeing what I opened.
My two colors were red and black while Kelly had blue and white. So I had five red cards, five black cards, five mountains, and five swamps. The next step was to open up my booster pack and select up to five cards.
That will do nicely!
I started the game with a fairly unexciting Goblin Tunneler.
The addition of Fiery Hellhound gave me an unblockable four damage per turn, if that's what I wanted to spend my time doing. And it was!
Meanwhile, Kelly had played Merfolk Mesmerist and was using it to whittle away at my library. And considering that my library was only 25 cards to begin with, it was a pretty good plan. And then he got his white cards working together.
The griffin plan was okay in principle, but I was way ahead on damage, so they were mostly ornamental. And then my bomb appeared, putting Kelly on a deadline.
Boom! Inferno Titan! Kelly was knocked down to five life and had to scramble a bit to stay alive. He played Aether Adept to bounce my Fiery Hellhound, so the only damage he couldn't stop was a Tormented Soul (for one damage) and the Inferno Titan's three, should I choose to throw all the damage at Kelly's face. He'd be at one life, but he'd still be alive until his turn.
...or so he thought. This picture shows Kelly thinking through the options, never dreaming that the Taste of Blood in my hand was about to kill him.
Sorry! That turned into a game recap, didn't it? Hopefully, it has given you a feel for what to do with the Booster Battle Pack.