Your Troops will consist of Capos and Buttonmen.  To gain Capos, you must recruit them at the Night Club in the Street Map.  To gain Buttonmen, they must first come from the Training facilities in the Mansion Map.  All of your Troops will then be housed at the Mills Terrace.  You can have up to 3 Capos leading a Troop of Buttonmen at one time, but you will have have to improve your power to unlock these Capo slots.  If your Buttonmen get wounded in Battle, they will need to heal at the Hospital.  If they get killed in Battle, you will have to train more Buttonmen to regain the power you lost.