http://www.wizards.com/Magic/Magazine/Article.aspx?x=mtg/daily/arcana/1152

Join the Boros Legion and become part of a unified attack force! The "Boros Battalion" deck hammers that point home by way of the battalion mechanic. Whenever you attack with a creature that has battalion and at least two other creatures, an effect that makes your assault even more powerful happens!

You'll want to speed out of the gates by casting as many creatures as possible during your early turns. Your mission is to control three creatures that can attack, so don't take risks early on. Attack only when the way is clear. Once you have a battalion assembled, use instants and sorceries like Shielded Passage and Aerial Maneuver to ensure you keep enough creatures around to continue the siege.

If your opponent decides to leave an entire bunker's worth of blockers in the way, no problem. Mark for Death limits your opponent's blocking options, and Righteous Charge helps inspire your entire army to rush into the fray and overrun the opponent. Act of Treason lets you borrow an opposing creature—perfect for completing your battalion and leaving the defense lacking.

If you're looking for larger creatures to add to your arsenal, check out Thundermaw Hellkite from the Magic 2013 core set or Hellrider from the Dark Ascension set. They both have haste, so they immediately hit hard, possibly triggering battalion abilities out of nowhere. Increasing Devotion, also from the Dark Ascension set, makes sure your armies are plentiful, giving you five creature tokens the first time around and ten if cast again using flashback!