How do I play?
well...read the rules section or go to 4chan.org/tg/ (beware of possible NSFW content) and ask around. The best way is to go to a hobby shop and watch some games.
Doesn't it cost a lot?
...Yes. To start out anyway. A basic starter kit to learn how to play costs $70 and includes two small armies (approx. 300 pts each), dice, a rulebook and some measuring sticks. A Single army battleforce is $90-95 depending on the army.
What's with all the dice?
Dice are used to decide most of the random elements of the game. Things like how many attacks hit a model, how many of those wound, and how many wounds are stopped by the model's armor.
Where can I get Models?
Check out your local hobby shop for models. I go to Your Hobby Place in Martinsburg. Failing that check ebay, Amazon, or GW's site and peruse what they have.
How do I choose my army?
Most people will tell you to go with whichever army looks the coolest to you. I advocate checking out how each army plays before you buy anything. Borrow and army, play some games, figure out what you like to do on the tabletop. Then spen $300 on an army.